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Maths Puzzle
Numerical Ability
A can do a piece of work in 20 days. he works at it for 5 days and then B finishes it in 10 more days. In how many days will A and B together finish the work?
a) 8 days b) 10 days c) 12 days d) 6 days
Read Solution (Total 4)
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- ANS: 8 DAYS.
A can do a work in 20 days then A's 1 day work will be 1/20, then it's 5 day work will be 5/20.
so remaining work is 15/20 is completed by B in 10 days.
so B's 1 day work will be =(1/10)*(15/20)=3/40.
(A+B)'s 1 day work will be (1/20)+(3/40)=1/8.
thus 8 days.
- 9 years agoHelpfull: Yes(3) No(0)
- Answer: 8 days
A completes full work in 20 days, so it will complete in 5 days=1/4work
Remaining work = 1-1/4=3/4
B completes 3/4 work in 10 days, so it will complete full work in 10*4/3 = 40/3 days.
A and B together can do the work in 1/20+3/40 = 5/40 = 8 days. - 9 years agoHelpfull: Yes(1) No(0)
- Let B do x% work in a day then
5*5%+10*x%=100%
x=7.5%
Now let y days to complete whole work when BOTH work together
5%*y +7.5%*y=100
y=8days
So ans is (a) - 9 years agoHelpfull: Yes(0) No(0)
- ANS: 8 DAYS.
A can do a work in 20 days then A's 1 day work will be 1/20, then it's 5 day work will be 5/20.
so remaining work is 15/20 is completed by B in 10 days.
so B's 1 day work will be =(1/10)*(15/20)=3/40.
(A+B)'s 1 day work will be (1/20)+(3/40)=1/8.
thus 8 days.
- 9 years agoHelpfull: Yes(0) No(0)
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