Mathematics Archives

121. At a ship the food was enough for 50 people. But after 10 days half of the men died due to some viral disease and the food is sufficient for as long as before. How long the food was sufficient for then?

A. 20

B. 60

C. 70

D. 50

✅ The correct answer is option A. 20.

122. Find the C.I. on a sum of Rs.1600 for 9 months at 20% per annum, interest being compounded quarterly?

A. Rs.17684

B. Rs.1684

C. Rs.2522

D. Rs.3408

✅ The correct answer is option C. Rs.2522.

123. A man sells Rs.5000, 12 % stock at 156 and uinvests the proceeds parity in 8 % stock at 90 and 9 % stock at 108. He hereby increases his income by Rs. 70. How much of the proceeds were invested in each stock?

A. 3600(8%), 4200(9%)

B. 4000(8%), 4200(9%)

C. 3600(8%), 4000(9%)

D. 4000(8%), 4000(9%)

✅ The correct answer is option A. 3600(8%), 4200(9%).
S.P of Rs. 5000 stock = Rs. [(156/100)*5000] = Rs. 7800.

Income from this stock = Rs. [(12/100)*5000] = Rs. 600.

124. A and B can finish a work 30 days if they work together. They worked together for 20 days and then B left. A finished the remaining work in another 20 days. In how many days A alone can finish the work?

A. 70

B. 50

C. 40

D. 60

✅ The correct answer is option D. 60.
Amount of work done by A and B in 1 day = 1/30

125. A is thrice as good a work man as B and takes 10 days less to do a piece of work than B takes. B can do the work in:___________?

A. 15 days

B. 14 days

C. 16 days

D. 30 days

✅ The correct answer is option A. 15 days.
Raio of times taken by A and B = 1 : 3

If the difference of time is 2 days, B takes 3 days. If the difference of time is 10 days.

B takes [3/2×10]=15 days

126. A garrison has provision for 30 days for certain men. If 2/3 of them do not attend the mess then the food will last for?

A. 50 days

B. 90 days

C. 65 days

D. 55 days

✅ The correct answer is option B. 90 days.

127. A box contains 3 blue marbles, 4 red, 6 green marbles and 2 yellow marbles. If two marbles are picked at random, what is the probability that they are either blue or yellow?

A. 3/22

B. 4/21

C. 2/21

D. 1/14

✅ The correct answer is option C. 2/21.

128. A and B can complete a work in 15 days and 10 days respectively. They started doing the work together but after 2 days B had to leave and A alone completed the remaining work. The whole work was completed in___________?

A. 8 days

B. 10 days

C. 12 days

D. 15 days

✅ The correct answer is option C. 12 days.
(A.+ B)’s 1 day’s work = ( 1/15 + 1/10 ) = 1/6 Work done by A and B in 2 days = ( 1/6 X 2 ) = 1/3 Remaining work = ( 1 – 1/6 ) = 2/3

Now, 1/15 work is done by A in 1 day. so 2/3 work will be done by A in ( 15 X 2/3 ) = 10 days Hence, total time taken = (10 + 2) = 12 days.

129. If Rs. 10 be allowed as true discount on a bill of Rs. 110 due at the end of a certain time, then the discount allowed on the same sum due at the end of double the time is:

A. Rs. 20

B. Rs. 21.81

C. Rs. 22

D. Rs. 18.33

✅ The correct answer is option D. Rs. 18.33.

130. A, B and C together earn Rs.150 per day while A and C together earn Rs.94 and B and C together earn Rs.76. The daily earning of C is:__________?

A. 10 Rs,

B. 15 Rs,

C. 20 Rs.

D. 25 Rs.

✅ The correct answer is option C. 20 Rs..
B’s daily earning = Rs.(150-94)= Rs.56

A’s daily earning = Rs.(150-76)= Rs.74

C’s daily earning = Rs.[(150-(56+74)]=Rs.20