AFCAT I 22 Jan 2025 Shift 2 Paper

Let the total work be 90 units.
Efficiency of X=90∕30=3 units/day
Efficiency of Y=90∕45=2 units/day
Efficiency of Z=90∕90=1 unit/day
Let total time taken to complete the work be 2 d days
Here X has worked for all the time but Y and Z has worked for only half the time.
According to the question -
( Efficiency of X )×2d+( Efficiency of Y +Z)×d=90
‌⇒3×2d+(2+1)d=90
‌⇒9d=90
‌⇒2d=20‌ days ‌
∴ The work can be completed in 20 days.