A cooker is marked at ₹12,500. The dealer allows successive discounts of 6%, 6% and 4% on it. What is the net selling price of the cooker?
- (a)₹12,320.60
- (b)₹10,306
- (c)₹10,603.20
- (d)₹12,230
Answer
Why
Correct — C. Successive discounts multiply; they are never added. Each one leaves a fraction of the price that reached it: 94%, then 94%, then 96%.
12,500 × 0.94 = 11,750
11,750 × 0.94 = 11,045
11,045 × 0.96 = ₹10,603.20 → option (c)
One line instead of three: 12,500 × 0.94 × 0.94 × 0.96 = 12,500 × 0.848256.
Why the others are wrong
- (a)₹12,320.60 — ₹12,320.60 is only 1.4% below the ₹12,500 marked price, while the three discounts together remove about 15% of it. No step in the chain leaves the price that close to the marking.
- (b)₹10,306 — ₹10,306 is ₹10,603 with the 3 and the 6 swapped, and it also drops the paise. The third step gives 11,045 × 0.96 = 10,603.20 exactly.
- (d)₹12,230 — ₹12,230 is 2.16% below the marked price. Like option (a) it treats the reductions as trivial instead of compounding to roughly 15%.
Concept
A discount of d% leaves a multiplier of (1 − d⁄100). Chain three of them and the multipliers multiply:
0.94 × 0.94 × 0.96 = 0.848256
So the single equivalent discount is 1 − 0.848256 = 15.1744%, not the 16% you get by adding 6 + 6 + 4. Successive discounts always come to less than their sum, because each later cut is taken on an already reduced price.
Multiplication commutes, so the order of the three discounts makes no difference to the final price.
The answer carries paise, which is the fastest way to spot it: 12,500 × 0.848256 = 10,603.20 exactly, and only one option is written to two decimals.
Key facts
- Successive discounts of 6%, 6% and 4% leave 0.94 × 0.94 × 0.96 = 0.848256 of the marked price.
- That is a single equivalent discount of 15.1744%, less than 6 + 6 + 4 = 16%.
- 12,500 × 0.848256 = ₹10,603.20.
- Selling price = marked price − discount, with the cost price playing no part in this question.
Study next
Common traps
- Adding 6 + 6 + 4 to 16% and taking 84% of ₹12,500, which gives ₹10,500.
- Applying the 4% to the marked price instead of to the twice-reduced price.
- Rounding the paise away and settling for a whole-rupee option.
The three-discount version recurs at 12 Sep 2024, 09:00, Quant Q.2 (₹5,000 at 20%, 15% and 10%, keyed ₹3,060) and at 10 Sep 2024, 16:00, Quant Q.3 (₹1,000 at 20%, 30% and 10%, keyed ₹504).
SSC also runs it backwards: 18 Sep 2024, 12:30, Quant Q.3 gives a ₹150 toy sold at ₹105 after two discounts and asks for the missing rate.
Related PYQs
No directly related past PYQ was found.