Time and Work Questions

Multiple choice
  1. $3$
  2. $5$
  3. $15$
  4. $20$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Original workers = 12, days = 10. New workers = 12 * (1/3) = 4. Using M1D1 = M2D2, 12 * 10 = 4 * D2, so D2 = 30 days. The question asks for 'how many more days', which is 30 - 10 = 20.

Multiple choice
  1. $Rs. 130$
  2. $Rs. 185$
  3. $Rs. 70$
  4. Can't be determined

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Kaushlaya (K) = 1/20, Kaikeyi (Kk) = 1/25. In 10 days, K does 10/20 = 1/2 work, Kk does 10/25 = 2/5 work. Total work done by K and Kk = 1/2 + 2/5 = 9/10. Sumitra (S) did 1 - 9/10 = 1/10 of the work. Share of S = (1/10) * 700 = 70.

Multiple choice
  1. $5\displaystyle\frac{5}{11}$
  2. $5\displaystyle\frac{6}{11}$
  3. $6\displaystyle\frac{5}{11}$
  4. $6\displaystyle\frac{6}{11}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

P's total work time = 12 * 8 = 96 hours. Q's total work time = 8 * 10 = 80 hours. Rates: P = 1/96, Q = 1/80. Combined rate = (5+6)/480 = 11/480. Time for 8 hours/day = (480/11) / 8 = 60/11 = 5 and 5/11 days.