9. A and B can do a job together in 25 days. After 15 days of working together, B leaves. If A
completes the remaining part of the job in 20 days, how long would each take to complete
the job, working separately?
10. 8 men or 12 women can do a job in 25 days. In what time can 6 men and 11 women do it?
11. A, B and C can do a job in 12 h, 20 h and 30 h respectively. If they all work together, how
long will they take to complete the job?
Answers
Answer:
A and B can do a job together in 25 days. After 15 days B leaves. If A completes the remaining part of the job in 20 days how long would each take to complete the job, working separately? So it would take A double time to do the work so it should take 50 days to do the work instead of 25 days.19-May-2020
Answer:
9)A can do a piece of work in 50 days
B can do a piece of work in 50 days
10)15 days
11)6 days
Step-by-step explanation:
9)Given,
A and B can do a job together in 25 days.
A+B=1/25
After 15 days of working together, B leaves.
A+B works for 15 days
A+B=15/25
A+B=3/5 parts
B left
A completes the remaining work in 20 days
let x be A's individual work
remaining work is 1-3/5=2/5 work
2/5=20/x days
x=50 days
A can complete a work in 1/50 days
substitute A in A+B=1/25
B=1/25-1/50
B=1/50 days
10)
Given,
8 men or 12 women can do a job in 25 days.
we know,
work=men*days*hours
8 men*25 days then
6 men in x days
if work is same then
8*25=6*x
100/3=x
like wise,
12 women*25 days=11 women* x days
x days=300/11
total 6 men+11 women is,
3/100+11/300=20/300
=1/15 days
11)Given,
A, B and C can do a job in 12 h, 20 h and 30 h respectively.
If they all work together, how long will they take to complete the job?
A+B+C=1/12+1/20+1/30
A+B+C=10/60
A+B+C=1/6 days