Answer this question.. HCL question

A man and his son planned to paint their own house. The man alone can do in 20 days. He paints for 4 days and then his son completed in 8 days. Find how many days will they take working together? a) 12 days b) 11 days c) 7 days d) 8 days

Vishal
18 जनवरी
2780 दृश्य
5 उत्तर

Your Answer

Shreya
14 जून

It is easy one.

Answer is option (c) 7 days
Explanation:
Man's 1 day work = 1/20
Then 4 days work = 4/20 = 1/5
Remaining work = 1 - 1/5 = 4/5
Now, 4/5 work is done by the son in 8 days.
Then, whole work will be done by him in (8 x 5/4) days = 10 days.
Then his 1 day work = 1/10
The man and his son's 1 day work = 1/10 + 1/10 = 3/10
They will complete the work together in 20/3 days = 6 2/3 days = 7 days(nearly).
Hence the answer is 7 days.