Question

a man spent rs 564 in buying goose and duck , if each goose cost rs 7 and each duck cost rs 3 and if the total no of birds bought was 108 , how many of each did he buy

Answer 1

Let the no. of geese bought be x.
So, the no. of ducks = 108 - x.
Therefore, the equation becomes:
7x + 3 * (108 - x) = Rs 564
7x + 324 - 3x = 564
4x = 564 - 324
4x = 240
x = 60
Thus the no. of geese is 60.
The no. of ducks = 108 - x.
So, 108 - 60 = 48
Thus, no. of ducks is 48.

Answer 2

let the no of ducks he bought be x
so the no of geese bought will be 108-x
cost of each goose is Rs.7
total cost of geese =7(108-x)
cost of each duck is Rs.3
total cost of duck is 3x
ATQ,
3x+7(108-x)=564
⇒3x+756-7x=564
⇒756-4x=564
⇒4x=192
⇒x=48
So the no of ducks bought is 48 
The no of geese bought is 108-48=60