The price of a product is decreased by x% and then increased by x%. The final price becomes 10% less than the original. What is the value of x (approximately)?
किसी वस्तु का मूल्य पहले x% घटाया जाता है और फिर x% बढ़ाया जाता है। अंतिम मूल्य मूल मूल्य से 10% कम हो जाता है। x का लगभग मान ज्ञात कीजिए।
This Question Asked In:
SSC, CGL MAINS 2026
Correct Answer :D - 32%
Detailed Text Solution
Let the original price be 100.
After decreasing by x%:
Price = 100(1 − x/100)
After increasing by x%:
Final price = 100(1 − x/100)(1 + x/100)
Using identity (a − b)(a + b) = a² − b²:
Final price = 100(1 − x²/10000)
Given final price is 10% less than original:
So final price = 90
100(1 − x²/10000) = 90
1 − x²/10000 = 0.9
x²/10000 = 0.1
x² = 1000
x = √1000 ≈ 31.62%
Thus, x ≈ 32%.