UPSC CAPF Assistant Commandant Model Paper 5

GIVEN:
x + y < 20
CALCULATION:
3x + 5y = 81
3x = 81 – 5y
To get integer value of ‘x’ value of ‘y’ must be a multiple of 3.
Let y = 3; x = 22 => x + y = 25 [Invalid]
Let y = 6; x = 17 => x + y = 23 [Invalid]
Let y = 9; x = 12 => x + y = 21 [Invalid]
Let y = 12; x = 7 => x + y = 19 [Valid]
Let y = 15; x = 2 => x + y = 17 [Valid]
∴ 2 possible solutions are there.