Question

Indu and Ramadhir can complete a task in $25$ days and $50$ days respectively. How long would Indu take to complete the task if Ramadhir assists her every second day $?$

• A. $10$ days
• B. $12$ days
• C. $15$ days
• D. $20$ days

Answer 1

The correct option is D $20$ days

Indu can complete task in 25 days

Indu's speed $=x$

Ramadhir can complete task in 50 days

Ramadhir's speed $=x\times \frac{25}{50}=\frac{x}{2}$ every second day

If Ramadhir assist Indu then

Indu's speed $=x+\frac{x}{4}=\frac{5x}{4}$

Task completion time $=\frac{25x}{\frac{5x}{4}}=20$ days