A shopkeeper bought locks at a rate of 8 locks for Rs 34 and sold them at a rate of 12 locks for Rs 57. Calculate:
1. his gain percent and
2. the number of locks he should sell to earn a profit of Rs 45. (PLZ answer soon exam approaching)
CP of 8 locks = 34
∴CP of 1 lock = = 4.25
SP of 12 locks = 57
∴SP of 1 lock = = 4.75
Thus, gain % is given by
where
Gain per lock = SP - CP = 4.75 - 4.25 = 0.50
Total profit to be earned = 45
∴ Number of locks to be sold = = 90
Thus, the shopkeeper needs to sell 90 locks to earn a profit of Rs 45.