a man bought bananas at the rate of rs.20 per dozen and sold them at th rate of 10 for rs 25. find his gain or loss per cent.

20 rs per dozen .. suppose he bought x dozen

then ... total CP = 20 * x = 20x

he bought x dozen ... so he bought total x * 12 = 12x bananas

so 12 x bananas for rs. 20 x

so 1 banana for how many rupess.

so ,, 20x * 1 / 12 x = 5 / 3 rupess .......

now he sold 10 bananas for 25 rupeess..

so 1 banan for how much = 25/10 = 2.5 rupees.........

he is gaining here bcoz 2.5 5/3 rupees

so .. 25 /10 5/3 rupees...( 2.5 is wrote as 25 / 10 )

so ... profit = 25/10 - 5/3 = 25 /30 = 5/6

so P% = P/ CP * 100

=( 5/6 ) / (5/3) *100

= 5/6 * 3/ 5 * 100

= 50% profit........

hope that helps......

so CP = 20 * x = 20x

the last line in my previous answer was typed by mistake..............

here u can refer

20 rs per dozen .. suppose he bought x dozen

then ... total CP = 20 * x = 20x

he bought x dozen ... so he bought total x * 12 = 12x bananas

so 12 x bananas for rs. 20 x

so 1 banana for how many rupess.

so ,, 20x * 1 / 12 x = 5 / 3 rupess .......

now he sold 10 bananas for 25 rupeess..

so 1 banan for how much = 25/10 = 2.5 rupees.........

he is gaining here bcoz 2.5 5/3 rupees

so .. 25 /10 5/3 rupees...( 2.5 is wrote as 25 / 10 )

so ... profit = 25/10 - 5/3 = 25 /30 = 5/6

so P% = P/ CP * 100

=( 5/6 ) / (5/3) *100

= 5/6 * 3/ 5 * 100

= 50% profit........

hope that helps......