Question

Rahul can finish one-fifth of his homework in one hour. Neha can finish threeseventh of her homework in one hour thirty minutes and riya can finish three fourth of her homework in three hours thirty minutes. If all of them start their homework at 12.00 p.M. And can go to play as soon as they all finish their homework, when can they start to play, if they take a break at 3.30 p.M. For thirty minutes?

Answer 1

Rahul, Neha and Riya can start to play at 5: 30 pm , 3: 30 pm and 5: 10 pm respectively.

Explanation

Rahul can finish $\frac{1}{5}th$ of his homework in 1 hour. So, the time required to finish his whole homework $= 1 \div \frac{1}{5}= 5$ hours.

Neha can finish $\frac{3}{7}th$ of her homework in 1 hour 30 minutes or in 1.5 hours. So, the time required to finish her whole homework $= 1.5 \div \frac{3}{7}= 1.5 \times \frac{7}{3}=3.5$ hours = 3 hours 30 minutes.

Riya can finish $\frac{3}{4}th$ of her homework in 3 hours 30 minutes or in 3.5 hours. So, the time required to finish her whole homework $=3.5\div \frac{3}{4}=3.5\times \frac{4}{3}=4\frac{2}{3}hours$ = 4 hours 40 minutes.

All of them start their homework at 12.00 p.m. and they take a break at 3.30 p.m. for 30 minutes.

As Neha is taking 3 hours 30 minutes to complete the homework, that means she can start to play at (12 p.m. + 3 hours 30 minutes) = 3:30 p.m. and she don't need a 30 minutes break.

Rahul can start to play at:  (12 p.m. + 5 hours +30 minutes break) = 5: 30 p.m.

and Riya can start to play at:  (12 p.m + 4 hours 40 minutes +30 minutes break) = 5: 10 p.m.

Answer 2

Answer:

answer B is the final 5.30 p.m.