65% of fishes in a pond were carps and the rest were angelfish. When 324 fishes consisting of carps and angelfish were added to the pond,percentage of carps increased by 10% while the number of angelfish doubled. How many carps were added to the pond?

1 Answer
Apr 19, 2018

The number of carps added in pond are #261#

Explanation:

Percentage of angelfishes were #100-65=35%# before adding.

Percentage of angelfishes were #100-75=25%# after adding

Let the number of total fishes in pond were #x# before adding.

The number of angelfishes in pond were #0.35 x# before adding.

The number of total fishes in pond is #x+324# after adding.

The number of angelfishes in pond is #0.25(x+324)# after adding.

By given condition, #0.25(x+324)=2*0.35 x# or

#0.25 x+81=0.7 or 0.7 x-0.25 x=81 :. 0.45 x = 81 # or

# x = 81/0.45= 180 :. 0.35 x=0.65*180= 117 #

The number of carps in pond were #117# before adding.

#0.75(x+324) = 0.75 * 504 = 378 :. 378-117= 261#

The number of carps in pond are #378# after adding.

The number of carps added in pond are #261# [Ans]