Advertisements
Advertisements
Question
A can-do `1/4` of work in 5 days and B can do `1/3` of the same work in 10 days. Find the number of days in which both working together will complete the work.
Solution
A can-do `1/4` of work in = 5 days
A can-do 1 work in = 5 × 4 days
= 20 days
B can do `1/3` of work in = 10 days
B can do 1 work in = 10 × 3 days
= 30 days
A's 1-day work =`1/20`
B's 1-day work =`1/30`
(A+B)'s 1 day work =`1/20+1/30`
`=(3+2)/60`
`=5/60`
`=1/12`
∴ A and B working together will complete the work in = 12 days
APPEARS IN
RELATED QUESTIONS
22 men can dig a 27 m long trench in one day. How many men should be employed for digging 135 m long trench of the same type in one day?
A train is moving with a uniform speed of 120 km per hour.
(i) How far will it travel in 36 minutes?
(ii) In how much time will it cover 210 km?
In a fort 150 men had provisions for 45 days. After 10 days, 25 men left the fort. How long would the food last at the same rate?
A contractor undertakes to dig a canal, 6 kilometers long, in 35 days and employed 90 men. He finds that after 20 days only 2 km of the canal has been completed. How many more men must be employed to finish the work on time?
Twelve typists, all working with the same speed, type a certain number of pages in 18 days working 8 hours a day. Find, how many hours per day must sixteen typists work in order to type the same number of pages in 9 days?
A can do a piece of work in 20 days and B in 15 days. They worked together on it for 6 days and then A left. How long will B take to finish the remaining work?
A and B complete a piece of work in 24 days. B and C do the same work in 36 days; and A, B, and C together finish it in 18 days. In how many days will:
(i) A alone,
(ii) C alone,
(iii) A and C together, complete the work?
A and B can do a piece of work in 40 days; B and C in 30 days; and C and A in 24 days.
- How long will it take them to do the work together?
- In what time can each finish it working alone?
A can do a piece of work in 10 days, B in 12 days, and C in 15 days. All begin together but A leaves the work after 2 days and B leaves 3 days before the work is finished. How long did the work last?
P and Q can do a piece of work in 12 days and 15 days respectively. P started the work alone and then after 3 days, Q joined him till the work was completed. How long did the work last?
