A clock was sold for ₹107.25. If the percentage of gain was numerically equal to the cost price, the cost of the clock was:
Answer & explanation
Correct answer: option 1
Best way is to go with answer options.
Check, Profit = 65 *65% = 42.25, it means S.P. = 65 + 42.25 = 107.25 (given)
Therefore, 65 is the cost price.
OR
Gain % = CP
⸫ \(\frac{Gain}{CP}\) × 100 = CP
SP = 107.25
= \(\frac{107.25-CP}{CP}\) × 100 = CP
10725 – 100 CP = CP2
CP2 + 100 CP – 10725 = 0
CP2 – 65 CP + 165 CP – 10725 = 0
CP (CP – 65) + 165 (CP – 65) = 0
(CP – 65) (CP + 165) = 0
⸫ CP = 65 (as CP cannot be negative)