time and work quiz 1

Explanation:

Ram’s 16 hr work = 16/24 = 2/3.

Remaining work = 1 – 2/3 = 1/3.

Using work and time formula: This will be completed in 1/3 × 18 i.e. 6 hrs.

So, total time taken to complete work = 16 + 6= 22 hrs.

Explanation: Their combined 4 day work = 4(1/10 + 1/15) = 12/20 = 3/5.

Remaining work = 1 – 3/5 = ⅖.

This means C did 2/5 work in 4 days, hence he can finish the complete work in 5/2 × 4 = 10 days.

Explanation:
A\'s work in 9 days = 9/12 = 3/4. Remaining work = 1/4.
This work was done by B in 1/4 × 16 = 4 days.
∴ B would have joined A after 9 – 4 = 5 days.

Explanation: A, B, C and D will together take ¼ + 1/12 = 4/12 = 1/3 ⇒ 3 days to complete the work.

Explanation:

A + B take 40 days. B alone takes 180 days.

∴ A will take 1/40 – 1/180 = 7/360 ⇒ 360/7 days.

B + C take 120 days.

∴ C alone will take 1/120 – 1/180 = 1/360

i.e. 360 days.

A & C together will take 7/360 + 1/360 = 8/360 ⇒ 360/8 = 45 days to complete the work.

Explanation:
D alone will take 1/20 – 1/50 – 1/60 = 4/300 = 1/75
⇒ 75 days to complete the work.

Explanation:
B & C do this work in 24 days. B alone does this work in 40 days.  C alone will take 1/24 – 1/40 = 2/120=1/60 ⇒ 60 days to finish the work.

Explanation:

A & B would have done 8/20 & 8/40 of the work respectively in 8 days.

Together they have done 3/5th of the work.

This implies that C has done 2/5th of the work.

Thus, C should be paid 2/5th of the amount i.e. 450 × 2/5 = Rs. 180.

Explanations

Tamatar would have done 47/60 work in 47 days.

The remaining work i.e. 13/60 must have been done by Daku and Tamatar together.

They can do the whole work in 60 × 70 / (60 + 70) = 60 × 70/130 = 420/13 days. So, they would have done 13/60 work in 420/13 × 13/60 = 7 days.

Therefore, Daku left the work after 7 days.