MCQ: Time & Work - 2 - SSC CGL MCQ

A can complete a piece of work in 20 days, and B can do the same work in 30 days.

To find out how many days A and B will take to finish the work together:

• Calculate the work done by A in one day: 1/20 of the work.
• Calculate the work done by B in one day: 1/30 of the work.
• Add both rates: 1/20 + 1/30 = 1/12 of the work per day.

Therefore, A and B working together can complete the work in 12 days.

Hence, Option B is correct.

Suraj's rate of work: Suraj can complete the work in 80 days, so his rate of work is 1/80 of the work per day.

Mangal's efficiency: Mangal is 60% as efficient as Suraj. So, Mangal's rate of work will be 60% of Suraj's rate, or (0.60 × 1/80) = 1/133.33 of the work per day.

Combined rate of work: When Suraj and Mangal work together, their combined rate is: (1/80) + (1/133.33).

To add these, we convert them to have a common denominator: (1/80) = 5/400 and (1/133.33) = 3/400.

So, the combined rate is (5/400) + (3/400) = 8/400 = 1/50.

Time taken to complete the work: Since their combined rate is 1/50, they will complete the work in 50 days.

Thus, the answer is 50 days.

80% of B = 125% of C
Efficiency → B : C = 125 : 80 = 25 : 16
Time → B : C = 16 : 25

Hence, Option C is correct.

Hence, Option B is correct.

First, find the normal rate of Pipe A:

• Pipe A fills 1000 liters in 150 minutes.
• Hence, its normal rate = 1000 / 150 = 6.6667 liters per minute.

Next, if it works at only 5% efficiency, its rate becomes:

• 5% of 6.6667 = 0.05 × 6.6667 = 0.3333 liters per minute (approximately).

Finally, to fill 60 liters at this reduced rate:

• Time required = 60 / 0.3333 ≈ 180 minutes.

Answer: 180 minutes (Option c).

Hence, Option C is correct.

Hence, Option D is correct.

Therefore, Pipe C can empty the filled tank in 75 minutes.

Pipe Q alone can fill the tank in

Hence, Option D is correct.

Reqd. time with 100% efficiency 

Hence, Option D is correct.

Hence, Option C is correct.

Time → Ajay : Vijay = 40 : 60 = 2 : 3
Efficiency → Ajay : Vijay = 3 : 2

Hence, Option B is correct.

Hence, Option C is correct.

Efficiency → A : B = 75 : 100 = 3 : 4

Hence, Option C is correct.

Let total work be LCM of (90, 60) = 180 unit
Ratio of number of days by Sarthak and Deepak = 90 : 60 = 3 : 2
Ratio of efficiency of Sarthak and Deepak = 2 : 3
Total unit in one day = 2 + 3 = 5 unit
Number of days taken = 180/5 = 36 days 
Hence, Option B is correct.

Hence, Option B is correct.