1. Mohan can finish a job in 60 days whereas Ram can finish the same job in 20 days. If they work together, the job will be over in-
A. 7.5 days
B. 15 days
C. 25 days
D. 55 days
(1/t=1/60+1/20=1/15
Time =15 days)
2. A can type 75 pages in 25 hrs. A and B working together can type 135 pages in 27 hrs. Time needed by B to type 42 pages is-
A. 24 hrs
B. 32 hrs
C. 21 hrs
D. 45 hrs
( A can type 3 pages in 1 hr
A and B can together type 5 pages in 1 hr
B can type 2 pages in an hour. So, B needs 21 hr to type 42 pages)
3. X can finish a job in 12 days, Y in 18 days and Z in 9 days. If they work together, the job will be over in-
A. 4 days
B. 6 days
C. 8 days
D. 9 days
(1/t=1/12+1/18+1/9=1/4
Time = 4 days)
4. A and B working together can move a field in 28 days. With the help of C they can finish the job in 21 days. If C works all alone the time needed by him to finish the job is-
A. 75 days
B. 67 days
C. 97 days
D. 84 days
(1/a+1/b=1/28
1/a+1/b+1/c=1/21
1/c=1/21-1/28=1/84
Time = 84 days)
5. A can do a job in 24 days. B is 50% more efficient than A. Then B can finish the job in-
A. 12 days
B. 24 days
C. 14 days
D. 18 days
(B needs half the time
B needs 24 x ½ =12 days)
6. A can do twice as much work as B. If they can together finish the job in 24 days, then working alone A would have finished the job in-
A. 54 days
B. 78 days
C. 72 days
D. 134 days
(1/x+1/2x=1/24
3/2x=1/24
X = 36 days)
7. If A takes half as long to do a piece of work as B takes and if C does it in same time as A and B together, and if all three working together will take 7 days to complete the work then B working alone would finish the job in-
A. 84 days
B. 43 days
C. 54 days
D. 42 days
(1/c=2/x+1/x=3/x
1/a+1/b+1/c=2/x+1/x+3/x=6/x
6/x=1/7…….x=42 days)
8. A can do a piece of work in 8 days and B can do the same work in 12 days. A and B together complete the job and get Rs. 200 as combined wages. B’s share in the wage will be-
A. 54 Rs
B. 67 Rs
C. 80 Rs
D. 90 Rs
(A:B=1/8:1/12=12:8
B’s share= 8/20 ×200=80)
9. A,B and C together do a piece of work for Rs. 5350. A working alone could do it in 5 days, B in 6 days and C in 7 days. The share of C is-
A. 1500 Rs
B. 1756 Rs
C. 1659 Rs
D. 1460 Rs
(A:B:C=1/5:1/6:1/7=42:35:30
C’s share =30/107×5350=1500)
10. A car goes 50 km in 5 hrs. What is the speed of car in m/s?
A. 4.225
B. 2.777
C. 2.857
D 5.566
(S=d/t…..50/5 km/hr
=10×1000/3600=(100/36 m)/s
=2.777m/sec)
