Latest Teaching jobs   »   Maths Questions for DSSSB Exam (Time...

# Maths Questions for DSSSB Exam (Time & Work) :20th June 2018: Solutions Dear Students!!! There is most general as well as a scoring section in all the competitive entrance examinations in the teaching field i.e “Mathematics”.Because in this section only one thing is work i.e your accuracy and that could be nourished with the daily practice. So, for this, we are providing you the daily quiz for all teaching exams i.e CTET Exam 2018, DSSSB Exam & amp; STET Exams.
Q1. 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) 71/2 days
(b) 15 days
(c) 20 days
(d) 80 days
Q2. A can do a piece of work in 20 days and B can do it in 30 days. Time taken by them to finish the job working together is
(a) 9 days
(b) 12 days
(c) 12.5 days
(d) 6 days
Q3. A can type 75 pages in 25 hours. A and B working together can type 135 pages in 27 hours. Time needed by B to type 42 pages is
(a) 24 hours
(b) 18 hours
(c) 21 hours
(d) 16 hours
Q4. A and B working together can do a piece of work in 7 days. B alone can do it in 8 days. After working alone on it for 5 days, B leaves the job. The work is taken over by A. The time needed by A to finish the job is
(a) 21 days
(b) 16 days
(c) 18 days
(d) None of above
Q5. X can finish a job in 12 days, Y is 18 days and Z in 9 days. If they work together the job will be over in
(a) 6 days
(b) 4 days
(c) 10 days
(d) 9 days
Q6. A can dig a well in 10 days, B can digit in 12 days and C can dig it is 15 days. If all work together the well be dug in
(a) 6 days
(b) 4 days
(c) 3 days
(d) 2 days
Q7. A can do a piece of work in 5 days, B in 4 days and A, B and C in 2 days. Time needed by C to complete the job is
(a) 20 days
(b) 40 days
(c) 10 days
(d) None of these
Q8. A and B working together can mow a field in 28 days. With 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) 42 days
(b) 84 days
(c) 63 days
(d) None of these
Q9. A and B working together can finish a job in 2 days. If B alone can do it in 3 days then A alone can do it in
(a) 6 days
(b) 4 days
(c) 8 days
(d) 5 days
Q10. A and B together can do a job in 24 days; B and C together in 18 days; and C and A together in 36 days. If they all work together the job will be over in
(a) 8 days
(b) 16 days
(c) 10 days
(d) 32 days

Solutions

S1. Ans.(b)
Sol.
1/t = 1/60 + 1/20 = 1/15
⇒ time = 15 days

S2. Ans.(b)
Sol.
1/t = 1/20 + 1/30 = 1/12
⇒ time = 12 days

S3. Ans.(c)
Sol. A can type 3 pages in 1 hour
A and B can together type 5 pages in 1 hour
⇒ B can type 2 pages in an hour
⇒ B needs 21 hours to type 42 pages

S4. Ans.(a)
Sol.
1/a + 1/8 = 1/7
⇒1/a = 1/7 – 1/8 = 1/56
5×1/8 + n×1/56 = 1
⇒ n = 21

S5. Ans.(b)
Sol.
1/t = 1/12 + 1/18 + 1/9 = 1/4
⇒ time = 4 days

S6. Ans.(b)
Sol.
1/t = 1/10 + 1/12 + 1/15 = 1/4
⇒ time = 4 days

S7. Ans.(a)
Sol.
1/5 + 1/4 + 1/C = 1/2
⇒1/C = 1/2 – 1/5 – 1/4 = 1/20
⇒ time = 20 days

S8. Ans.(b)
Sol.  According to the ques,
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

S9. Ans.(a)
Sol.
1/a + 1/3 = 1/2
⇒1/a = 1/2 – 1/3 = 1/6
⇒ time = 6 days

S10. Ans.(b)
Sol.
1/a + 1/b = 1/24
1/b + 1/c = 1/18
1/c + 1/a = 1/36