Question

(a) One-fourth of birds of a flock are at a river bank and one-fifth of that flock are in their nest. Remaining 22 birds are wandering in search of food. What is the number of birds which are in their nest?
(a) 40 (b) 18 (c) 10 (d) 8 ​

Answer 1

Lets take the total number of birds= X

Therefore, Birds are at the riverbank =x/4

Birds are in the nest =x/5

Remaining birds wandering for food=22

According to the question,

=> x/4+x/5+22 =X

=>9x/20+22=X

=>9x+440=20x

=>11x =440

=>x =40

Total number of birds =40

Therefore birds in the nest =x/5

=40/5

=8

Answer 2

Answer:

let the numbers of total birds be x

1/4x are at river

1/5x are in nest

remaining birds= x-(x/4+x/5)=x-9x/20=11x/20

22=11x/20

440/11=x

40=x

no. of birds in nest =1/5x= 1/5 ×40 =8