Basic Maths Mcqs MCQs

Two taps X and Y can fill a tank in 10 hrs. and 15 hrs.respectively.  If the both taps are opened together, the tank will be full in_________?

by
A. 3 hrs.
B. 4 hrs,
C. 5 hrs.
D. 6 hrs.
✅ The correct answer is option D. 6 hrs..
X’s 1 hour work = 1/10

Y’s 1 hour work = 1/15

(x+y)’s 1 hour work = 1/10+1/15=5/30=1/6

Both the taps can fill the tank in 6 hrs.

P and Q can complete a work in 15 days and 10 days respectively. They started the work together and then Q left after 2 days. P alone completed the remaining work. The work was finished in__________days.

by
A. 12
B. 15
C. 22
D. 20
✅ The correct answer is option A. 12.
Work done by P in 1 day = 1/15

Work done by Q in 1 day = 1/10

Work done by P and Q in 1 day = 1/15 + 1/10 = 1/6

Work done by P and Q in 2 days = 2 × (1/6) = 1/3

Remaining work = 1 – 1/3 = 2/3

Time taken by P to complete the remaining work 2/3 = (2/3) / (1/15) = 10 days

Total time taken = 2 + 10 = 12 days