Question 1

Q1. If 300 men can do a piece of work in 16 days, how many men would do (1/5) of the work in 15 days?
(a)56         (b)64            (c)60            (d)72

ANSWER:

work = 300 x 16

1/5th of work = 60 x 16

men required to complete it in 15 days = 60 x 16 / 15 = 64 (b)

question 11

Q11. 30 men working 5h a day can do a work in 16 days. In how many days will 20 men working 6 h a day do the same work?

Ans:

Work W = 30 x 5 x 16

Days required =  ( 30 x 5 x 16)/(20 x 6) = 20

HUMRAJ!!!!!!

Q5. Twenty workers can finish a piece of work in 30 days. After how many days could 5 workers leave the job so that the work is completed in 35 days?

Sol.

let after x days,

600 = 20x + 15(35 - x)

x = 15 days

Q4. If 20 men can build a

Q4. If 20 men can build a wall 112 metres long in 6 days, what length of a similar wall can be built by 25 men in 3 days?

Sol: The lenght of wall = 112 x 25 x 3/(20 x 6)= 70 metres.
 

Q8. If 27 kg of corn would

Q8. If 27 kg of corn would feed 42 horses for 21 days, in hour many days would 36 kg of it feed 21 horses?
(a)28 days
(b)42 days
(c)56 days
(d)31-1/2 days

Q12. A swimming pool can be

Q12. A swimming pool can be filled by an inlet pipe in 10 hours and emptied by an outlet pipe in 12 hours. One day the pool is empty and the owner opens the inlet pipe to fill the pool. However, he forgets to close the outlet. With both pipes open, how long will it take to fill the pool?

The alone time of the inlet pipe = 1/10 hours ,while that of outlet pipe =1/ 12 hours
When both the pipes are open then let "a" be the time to fill up the pool.
So, a(1/10-1/12)=1
=> a= 60 hours.
 

Q3. One pipe can fill a pool

Q3. One pipe can fill a pool 1.25 times faster than a second pipe. When both pipes are opened, they fill the pool in five hours. How long would it take to fill the pool if only the slower pipe is used?
Sol: Let the time taken by slower pipe to fill the pool= 1.25 a hours
So the alone time of slower pipe=1/1.25a
And the time taken by faster pipe= a
Alone time =1/a
A/q, 5(1/1.25a+1/a)=1
=> a= 9 hours
So slower pipe will take =9 x 1.25=11.25 hours

Q6. A, B and C can do a

Q6. A, B and C can do a work in 5 days, 10 days and 15 days respectively. They started together to do the work but after 2 days A and B left. C did the remaining work (in days)
(a)1
(b)3
(c)5
(d)4

Q7. If 20 men working 7

Q7. If 20 men working 7 hours a day can do a piece of work in 10 days, in how many days will 15 men working for 8 hours a day do the same piece of work?
(a)15-5/21 days
(b)11-2/3 days
(c)6-9/16 days
(d) 4-1/5 days

Q9. Shyam can do a job in 20

Q9. Shyam can do a job in 20 days, Ram in 30 days and Singhal in 60 days. If Shyam is helped by Ram and Singhal every 3rd day, how long will it take for them to complete the job?
(a)12 days
(b)16 days
(c)15 days
(d)10 days

Sol: 1 day work of shyam= 1/20
1 day work of ram=1/30
1 day work of Singhal =1/60

2 day work of shyam=2/20=1/10
1 day work of shyam,ram and singhal together=(1/20+1/30+1/60)=1/10
So, after every 3 days amount of work completed=1/5
So to complete the total work the days required=5 x 1/5 = 15 days

Ans: (c)15 days



 

Q13. If 12 boys can earn Rs

Q13. If 12 boys can earn Rs 240 in 5 days, how many boys can earn Rs 420 in 21 days?
(a)15 boys
(b)5 boys
(c)17 boys
(d)None of these

Sol: 12 boys can earn Rs 240 in 5 days
So, 1 boy can earn Rs 4 in 1 day
=> 20 boys can earn Rs 420 in 21 days

Ans: (d) None of these
 

Q10. A twice as good as a

Q10. A twice as good as a workman as B; and together they finish a work in 16 days. In how many days can it be done by each separately?

Sol: Let A can finish a work alone in a days ,so B can finish it in 2a days.
A/q, 16(1/a+1/2a)=1
=> a= 24 days and 2a= 48 days

A can finish it alone in 24 days ,while B can finish it alone in 48 days.
 

Q2. If 4 men or 7 boys do a

Q2. If 4 men or 7 boys do a work in 29 days, 12 men and 8 boys will do the same work in


Sol: A/q, 4 men can do a work in 29 days
=>1 man can do it in 29 x 4 days.
7 boys can do the work in 29 days
=>1 boy can do it in 29 x 7 days.
Suppose ,12 men and 8 boys can do the work in a days.
So, a[8/(29 x 7) + 12/(29 x 4)] = 1
Solving, a = 7days


 

Q13

Q13. If 12 boys can earn Rs 240 in 5 days, how many boys can earn Rs 420 in 21 days? Amount earned by 12boys in one day=240/5=48 Amount earned by each boy per day=48/12=4 simillarly, amount earned by X number of boys in one day=420/21=20. number of boys earns(Rs) 1 4 X 20 X=20/4=5 boys

Ans 13

ans) 5 boys.

Rupees are paid according to the work done so
12 * 5 = x * 21
------   --------
240         420

on solvig we get x = 5

ans 10

Ans) B  can do in 48 hrs and a in 24 hrs

but in vtu pgcet 2006 mca the

but in vtu pgcet 2006 mca the question is same but the options are a)9boys b)5boys c)12boys d)6boys i am not getting it