Quiz Discussion

If m men can do a work in r days, then the number of days taken by (m + n) men to do it is :

• 1]

  \(\frac{{{ \text{m}} + { \text{n}}}}{{{ \text{mn}}}}\)

• 2]

  \(\frac{{{ \text{m}} + { \text{n}}}}{{{ \text{mr}}}}\)

• 3]

  \(\frac{{{ \text{mr}}}}{{{ \text{m}} + { \text{n}}}}\)

• 4]

  \(\frac{{{ \text{r}}\left( {{ \text{m}} + { \text{n}}} \right)}}{{{ \text{mn}}}}\)

A can complete a piece of work in 36 days, B in 54 days and C in 72 days. All the three began the work the work together but A left 8 days before the completion of the work and B 12 days before the completion of work. Only C worked up to the end. In how many days was the work completed?

• 1] 24 days
• 2] 25 days
• 3] 27 days
• 4] 30 days

A cistern can be filled by two pipes in 20 and 30 minutes respectively. Both pipes being opened, when the first pipe must be turned off so that the cistern may be filled in 10 minutes more.

• 1] After 10 minutes
• 2] After 12 minutes
• 3] After 20 minutes
• 4] After 8 minutes

A can do \(\frac{1}{3}\) rd of work in 5 days and B can do the do \(\frac{2}{5}\)th of this work in 10 days. Both A and B, together can do the work in?

• 1]

  \({ \text{ 7}}\frac{3}{8}{ \text{ days}}\)

• 2]

  \({ \text{8}}\frac{4}{5}{ \text{ days}}\)

• 3]

  \({ \text{9}}\frac{3}{8}{ \text{ days}}\)

• 4]

  10 days

Shashi can do piece of work in 20 days. Tanya is 25% more efficient than Sashi. The number of days taken by Tanya to do the same piece of work is = ?

• 1] 15
• 2] 25
• 3] 18
• 4] 16

A and B completed a work together in 5 days. had A worked at twice the speed and B at half the speed, it would have taken them four days to complete the job. How much time would it take for A alone to do the work?

• 1] 10 days
• 2] 20 days
• 3] 25 days
• 4] 15 days
• 5] 24 days

10 men working 6 hours a day can complete a work in 18 days. How many hours a day must 15 men work to complete the same work in 12 days ?

• 1] 6 hours/day
• 2] 10 hours/day
• 3] 12 hours/day
• 4] 15 hours/day

If 5 men and 3 women can reap 18 acre of crop in 4 days, 3 men and 2 women can reap 22 acre of crop in 8 days, then how many men are required to join 21 women to reap 54 acre of crop in 6 days ?

• 1] 5
• 2] 6
• 3] 10
• 4] 12

A can do a piece of work in 70 days and B is 40% more efficient then A. Then the number of days taken by B to do the same work is = ?

• 1] 40 dayd
• 2] 60 days
• 3] 50 days
• 4] 45 days

A can do half of a piece of work in 1 day,where B can do full. B can do half the work as C in 1 day. The ratio of their efficiencies of work is = ?

• 1] 1 : 2 : 4
• 2] 2 : 1 : 4
• 3] 4 : 2 : 1
• 4] 2 : 4 : 1