Correct Answer - Option 2 : 4.6

**Given:**

Arjun is 15 times efficient than Ankit.

Ankit finish work in 75 days.

**Calculation**

Let the time taken by Arjun and Ankit together is x days

Arjun takes 5 days to complete a work(i.e 75/15)

Ankit takes 75 days to complete a work

According to question

Work done by Arjun in one day = 1/5

Work done by Ankit in one day = 1/75

Work done by Arjun and Ankit in one day = 1/x

⇒ (1/5) + (1/75) = 1/x

⇒ (15 + 1)/75 = 1/x

⇒ 16/75 = 1/x

⇒ 75/16 = x

⇒ 4.6 days = x

**∴ Arjun and Ankit work together and completes work in 4.6 days.**