Billu hammers 20 mails in 6 mins. Gopi does ghe same job in only 5 mins. How long will it take fo finish if billu hammers the first 5 nails, then gopi hammers for 3 mins then billu finishes the job
Answers
Step-by-step explanation:
Bill hammers 20 nails in 6 minutes.
==> It takes him 6/20 = 0.3 minutes to hammer one nail.
==> If the total job is 20 nails, then he does 1/6 of the job in 1 minute.
Jeff hammers 20 nails in 5 minutes.
==> It takes him 5/20 = 0.25 minutes to hammer one nail.
==> If the total job is 20 nails, then he does 1/5 of the job in 1 minute
the question doesn’t say what size job they’re assigned.
I’ll assume it’s a 20-nail job.
First step: Bill hammers 5 nails.
At 0.3 minutes per nail, that takes Bill 5 x 0.3 = 1.5 minutes
Second step: Jeff hammers for 3 minutes.
At 0.25 minute per nail, he adds 3/0.25 = 12 nails to Bill’s 5, for a total of 17 so far.
Third step: Bill finishes the job.
There are (20 - 17) = 3 nails left to go.
At 0.3 minutes per nail, this takes Bill 3 x 0.3 = 0.9 minutes.
First step. 1.5 minutes
Second step. 3 minutes
Third step. 0.9 minutes
Total. 5.4minutes