Question

Arjun and Akbar together complete a piece of work in 30 days. Arjun completes the work two times faster than Akbar. Find the time taken by Arjun to complete the work.
1. 45 days
2. 15 days
3. 20 days
4. 17 days

Answer 1

Correct Answer - Option 1 : 45 days
Given

Arjun and Akbar completes a work in 30 days.

Arjun efficiency = 2(Akbar's efficiency)

Calculation

Let the time taken by Arjun to complete a work is x days

So,time taken by Akbar to complete a work is 2x days.

Work done by Arjun in 1 day = (1/x) 

Work done by Akbar in 1 day = (1/2x)

Work done by Arjun and Akbar in 1 day = (1/30)

According to question

⇒ (1/x) + (1/2x) = 1/30

⇒ (2 + 1)/2x = 1/30

⇒ 3/2x = 1/30

⇒ (3 × 30)/2 = x

⇒ 45 days = x

∴ Arjun completes the work in 45 days.