Commercial Mathematics Weightage: 4–6 Marks 13 Questions Active (2026 + 2026 Imp + 2025 + 2024 + 2023 + 2020 + 2019 + 2018 + 2017)

01. Goods and Services Tax (GST) Previous Year Questions

Core Formula: Net Tax = Output GST − Input Tax Credit (ITC)

CISCE Examiner Observation & Common Deduction Pitfall

Candidates often confuse Intra-state (CGST + SGST) with Inter-state (IGST). On inter-state sales, only IGST applies; no CGST or SGST is charged.

ICSE 2026 Board Q1 Multiple Choice Question
1 Mark
A dealer in Delhi buys an article from a manufacturer in Mumbai for ₹12,000 and sells it to a consumer in Delhi at a profit of ₹3,000. If the rate of GST is 18%, the Integrated GST (IGST) paid by the dealer to the Central Government is:
(a) ₹0
(b) ₹540
(c) ₹2,160
(d) ₹2,700
View Verified Solution & Marking
Correct Option: (a) ₹0
Explanation Dealer bought inter-state (Mumbai → Delhi): Input IGST = 18% of ₹12,000 = ₹2,160.
Dealer sells intra-state (Delhi → Delhi): Output CGST = 9% of ₹15,000 = ₹1,350; Output SGST = 9% of ₹15,000 = ₹1,350.
The dealer utilizes Input IGST (₹2,160) to set off Output CGST (₹1,350) and part of Output SGST (₹810). No IGST is payable on sale to a local consumer in Delhi. Hence, IGST paid to Central Govt = ₹0.
ICSE 2026 Board Q2 Short Answer (Theory & Calc)
3 Marks
A shopkeeper buys a TV set from a wholesaler at a marked price of ₹25,000. He sells it to a customer at a discount of 10% on the marked price. If the sale is intra-state and the rate of GST is 12%, find the:
(a) discounted price of the TV set.
(b) amount paid by the customer to clear the bill.
View Verified Solution & Marking
Part (a) Marked Price = ₹25,000. Discount = 10% of ₹25,000 = ₹2,500.
⇒ Discounted Selling Price = ₹25,000 − ₹2,500 = ₹22,500. [1 Mark]

Part (b) Rate of GST = 12% (CGST 6% + SGST 6%).
Total GST = 12% of ₹22,500 = 0.12 × 22,500 = ₹2,700. [1 Mark]
Total Amount paid by customer = Selling Price + GST = ₹22,500 + ₹2,700 = ₹25,200. [1 Mark]
ICSE 2025 Board Q3 Multiple Choice Question
1 Mark
The marked price of an article is ₹1375. If the CGST is charged at a rate of 4%, then the price of the article including GST is:
(a) ₹55
(b) ₹110
(c) ₹1430
(d) ₹1485
View Verified Solution & Marking
CGST = 4% ⇒ Total GST rate = 2 × 4% = 8%.
Total GST Amount = 8% of ₹1375 = ₹110. [0.5 Mark]
Price of the article including GST = Marked Price + GST = ₹1375 + ₹110 = ₹1485. [0.5 Mark]
ICSE 2025 Board Q4 Commercial Mathematics • GST Billing
4 Marks
Refer to the given bill:
Article A: M.P. ₹190, Quantity 06, G.S.T. 12%
Article B: M.P. ₹50, Quantity 12, G.S.T. 18%
A customer paid ₹2000 (rounded off to the nearest ₹10) to clear the bill.
Note: 5% discount is applicable on an article if 10 or more such articles are purchased.
Check whether the total amount paid by the customer is correct or not. Justify your answer with necessary working.
View Verified Solution & Marking
Article A: Quantity is 6 (< 10), so no discount applies.
Total MP = 6 × 190 = ₹1140.
GST = 12% of ₹1140 = ₹136.80. Amount for Article A = ₹1140 + ₹136.80 = ₹1276.80. [1.5 Marks]

Article B: Quantity is 12 (≥ 10), so 5% discount applies.
Total MP = 12 × 50 = ₹600.
Discount = 5% of ₹600 = ₹30 ⇒ Selling Price = ₹600 − ₹30 = ₹570.
GST = 18% of ₹570 = ₹102.60. Amount for Article B = ₹570 + ₹102.60 = ₹672.60. [1.5 Marks]

Total Bill: ₹1276.80 + ₹672.60 = ₹1949.40.
Rounded off to the nearest ₹10 gives ₹1950.
Since the customer paid ₹2000, the total amount paid by the customer is NOT correct (the customer overpaid by ₹50). [1 Mark]
ICSE 2024 Board Q5 Multiple Choice Question
1 Mark
For an Intra-state sale, the CGST paid by a dealer to the Central government is ₹120. If the marked price of the article is ₹2000, the rate of GST is:
(a) 6%
(b) 10%
(c) 12%
(d) 16.67%
View Verified Solution & Marking
Correct Option: (c) 12%
For an intra-state sale, CGST = SGST = 1/2 of Total GST.
Given CGST = ₹120 ⇒ Total GST = 2 × 120 = ₹240.
Rate of GST = (Total GST / Marked Price) × 100% = (240 / 2000) × 100% = 12%. [1 Mark]
ICSE 2024 Board Q6 Commercial Mathematics • GST Billing
3 Marks
Rohan bought the following eatables for his friends:
1. Laddu: ₹500 per kg, Quantity: 2 kg, Rate of GST: 5%
2. Pastries: ₹100 per piece, Quantity: 12 pieces, Rate of GST: 18%
Calculate: (a) Total GST paid   (b) Total bill amount including GST.
View Verified Solution & Marking
Item 1 (Laddu): Cost = 2 × 500 = ₹1,000. GST = 5% of 1000 = ₹50. [1 Mark]
Item 2 (Pastries): Cost = 12 × 100 = ₹1,200. GST = 18% of 1200 = ₹216. [1 Mark]
(a) Total GST paid: 50 + 216 = ₹266. [0.5 Mark]
(b) Total bill amount: (1000 + 1200) + 266 = ₹2,466. [0.5 Mark]
ICSE 2023 Board Q7 Multiple Choice Question
1 Mark
The printed price of an article is ₹3,080. If the rate of GST is 10%, then the GST charged is:
(a) ₹154
(b) ₹308
(c) ₹30.80
(d) ₹15.40
View Verified Solution & Marking
$\text{GST charged} = 10\% \text{ of } ₹3,080 = \frac{10}{100} \times 3080 = ₹308$.
Correct Option: (b) [1 Mark]
ICSE 2023 Board Q8 Commercial GST Billing
3 Marks
Mrs. Arora bought the following articles from a departmental store:
S. No. Item Price Rate of GST Discount
1. Hair oil ₹1,200 18% ₹100
2. Cashew nuts ₹600 12% −
Find the:
  1. Total GST paid.
  2. Total bill amount including GST.
View Verified Solution & Marking
Item 1: Hair Oil
Taxable Selling Price = $1,200 - 100 = ₹1,100$.
GST on hair oil = $18\% \text{ of } ₹1,100 = 0.18 \times 1100 = ₹198$.

Item 2: Cashew Nuts
Taxable Selling Price = ₹600.
GST on cashew nuts = $12\% \text{ of } ₹600 = 0.12 \times 600 = ₹72$.

Part (a) Total GST $= 198 + 72 = \mathbf{₹270}$.1.5 Marks

Part (b) Total Bill $= \text{Total Taxable Price} + \text{Total GST} = (1100 + 600) + 270 = 1700 + 270 = \mathbf{₹1,970}$.1.5 Marks
ICSE 2020 Board Q9 Commercial GST Billing
4 Marks
Mr. Bedi visits the market and buys the following articles:
1. Medicines costing ₹950, GST @ 5%
2. A pair of shoes costing ₹3000, GST @ 18%
3. A Laptop bag costing ₹1000 with a discount of 30%, GST @ 18%.
(i) Calculate the total amount of GST paid.
(ii) The total bill amount including GST paid by Mr. Bedi.
View Verified Solution & Marking
Item 1 Medicines: Taxable value $= ₹950$. GST $= 5\% \text{ of } 950 = \mathbf{₹47.50}$. [1 Mark]
Item 2 Shoes: Taxable value $= ₹3,000$. GST $= 18\% \text{ of } 3000 = \mathbf{₹540.00}$. [1 Mark]
Item 3 Laptop Bag: Marked price $= ₹1,000$. Discount $= 30\% \text{ of } 1000 = ₹300$.
Taxable Selling Price $= 1000 - 300 = ₹700$.
GST $= 18\% \text{ of } 700 = \mathbf{₹126.00}$. [1 Mark]
Totals
(i) Total GST paid $= 47.50 + 540.00 + 126.00 = \mathbf{₹713.50}$. [0.5 Mark]
(ii) Total taxable amount $= 950 + 3000 + 700 = ₹4,650$.
Total bill amount $= ₹4,650 + ₹713.50 = \mathbf{₹5,363.50}$. [0.5 Mark]
ICSE 2026 Imp Q10 Multiple Choice Question
1 Mark
The marked price of a smart TV is ₹ 18,000. The rate of GST is $18\%$. The price paid by the customer for the smart TV is:
(a) ₹ 12,960
(b) ₹ 19,620
(c) ₹ 18,000
(d) ₹ 21,240
View Verified Solution & Marking
Solution $\text{Marked Price} = \text{₹ } 18,000$.
$\text{GST} = 18\% \times 18000 = \frac{18}{100} \times 18000 = \text{₹ } 3240$.
$\text{Price paid by customer} = 18000 + 3240 = \mathbf{\text{₹ } 21,240}$.
Correct Answer: (d) ₹ 21,240 [1 Mark]
ICSE 2026 Imp Q11 Commercial Mathematics: Component Repairs & GST
3 Marks
A computer mechanic charges repairing cost of different components as tabulated below:
Component Repairing cost (₹) Discount (%)
A₹ 500020%
B₹ 650030%
The rate of GST is $18\%$. Find the total:
  1. discount
  2. amount of GST
View Verified Solution & Marking
Step 1 (a) Total discount:
Discount on Component A $= 20\% \times 5000 = \text{₹ } 1000$.
Discount on Component B $= 30\% \times 6500 = \text{₹ } 1950$.
$\mathbf{\text{Total Discount} = 1000 + 1950 = \text{₹ } 2950}$. [1.5 Marks]
Step 2 (b) Total GST amount:
Taxable amount for A $= 5000 - 1000 = \text{₹ } 4000$.
Taxable amount for B $= 6500 - 1950 = \text{₹ } 4550$.
Total taxable value $= 4000 + 4550 = \text{₹ } 8550$.
$\mathbf{\text{Total GST} = 18\% \times 8550 = 0.18 \times 8550 = \text{₹ } 1539}$. [1.5 Marks]
ICSE 2017 Board Q12 Commercial Mathematics & Sales Tax
3 Marks
The catalogue price of a computer set is ₹42,000. The shopkeeper gives a discount of 10% on the listed price. He further gives an off-season discount of 5% on the discounted price. However, sales tax at 8% is charged on the remaining price after the two successive discounts. Find:
(i) the amount of sales tax a customer has to pay
(ii) the total price to be paid by the customer for the computer set.
View Verified Solution & Marking
Successive Discounts
Catalogue Price $= ₹42,000$.
First Discount $(10\%) = \frac{10}{100} \times 42,000 = ₹4,200$.
Price after 1st discount $= 42,000 - 4,200 = ₹37,800$.
Off-season Discount $(5\%) = \frac{5}{100} \times 37,800 = ₹1,890$.
Final Selling Price before tax $= 37,800 - 1,890 = ₹35,910$. [1 Mark]
(i) Sales Tax (8%)
$$\text{Sales Tax} = \frac{8}{100} \times 35,910 = \mathbf{₹2,872.80}$$ [1 Mark]
(ii) Total Amount Paid
$$\text{Total Price} = 35,910 + 2,872.80 = \mathbf{₹38,782.80}$$ [1 Mark]
Answers: (i) Sales tax $= ₹2,872.80$, (ii) Total price $= ₹38,782.80$.
ICSE 2017 Board Q13 Value Added Tax (VAT)
3 Marks
The printed price of an air conditioner is ₹45,000/-. The wholesaler allows a discount of 10% to the shopkeeper. The shopkeeper sells the article to the customer at a discount of 5% of the marked price. Sales tax (under VAT) is charged at the rate of 12% at every stage. Find:
(i) VAT paid by the shopkeeper to the government.
(ii) The total amount paid by the customer inclusive of tax.
View Verified Solution & Marking
Step 1: Wholesaler to Shopkeeper Printed Price $= ₹45,000$.
Cost price to shopkeeper $= 45,000 - 10\% \text{ of } 45,000 = ₹40,500$.
Input Tax paid by shopkeeper $= \frac{12}{100} \times 40,500 = ₹4,860$.
Step 2: Shopkeeper to Customer
Selling price to customer $= 45,000 - 5\% \text{ of } 45,000 = ₹42,750$.
Output Tax collected $= \frac{12}{100} \times 42,750 = ₹5,130$.
(i) VAT Paid by Shopkeeper
$$\text{VAT} = \text{Output Tax} - \text{Input Tax} = 5,130 - 4,860 = \mathbf{₹270}$$ [1.5 Marks]
(ii) Total Amount Paid by Customer
$$\text{Total Price} = 42,750 + 5,130 = \mathbf{₹47,880}$$ [1.5 Marks]
Answers: (i) VAT paid $= ₹270$, (ii) Total amount paid $= ₹47,880$.

Archive Expansion Slot • 2014–2025 PYQs

Questions from 2025 Specimen, 2024, 2023, 2022 Sem-1/2, and 2020–2014 board exams for Chapter 1 are being indexed into this collection.