Question

By selling 12 oranges for one rupee, a man loses 20%. How many for a rupee should he sell to gain 20%?

Answer 1

Answer:

Step-by-step explanation:

SP=1 rs

L%=20%

CP=100/80*1

=1.5

CP=1.5

G%=20

SP=100+G%/100*CP

120/100*1.5

SP=1.8

Is it correct

Answer 2

Answer:

8 oranges per rupee

Step-by-step explanation:

Let C be the man's cost in rupees per orange.

His cost for 12 oranges is then 12C.

If he makes a 20% selling them, then the selling price is:

(100 - 20)% of 12C  =  80% of 12C = 0.8 × 12C = 9.6C

We're given that this "20% loss" selling price is 1, so

9.6C = 1   =>  C = 1 / 9.6

To make a profit of 20%, his selling price must be

(100 + 20)% of C  =  120% of C  = 1.2 × C = 1.2 / 9.6 = 0.125.

But we don't want selling price as "rupees per orange".

We're asked for "oranges per rupee"!

So we need to invert the "rupees per orange" figure to get:

1 / 0.125 = 8 oranges per rupee.