Advertisements
Advertisements
Question
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?
Solution
A's one day's work =`1/10`
B's one day's work =`1/12`
C's one day's work =`1/15`
A, B and C's one day's work =`1/10+1/12+1/15`
`=(6+5+4)/60=15/60=1/4`
Let the work completed in x days
∴ A's 2 days work + B's (x − 3) days work + C's x days work = 1
`⇒2xx1/10+("x"-3)xx1/12+"x"xx1/15=1`
`⇒1/5+("x"-3)/12+"x"/15=1`
`(12+5"x"-15+4"x"=60)/60` ...(L.C.M of 5, 12, 15 = 60)
⇒ 9x = 60 − 12 + 15
⇒ 9x = 63
`⇒"x"=63/9=7`
∴ Work will last for 7 days
APPEARS IN
RELATED QUESTIONS
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?
12 pipes, all of the same size, fill a tank in 42 minutes. How long will it take to fill the same tank, if 21 pipes of the same size are used?
72 men do a piece of work in 25 days. In how many days will 30 men do the same work?
In order to complete a work in 28 days, 60 men are required. How many men will be required if the same work is to be completed in 40 days?
A can do a piece of work in 10 days and B in 15 days. How long will they take together to finish it?
A and B together can do a piece of work in `6 2/3` days, but B alone can do it in 10 days. How long will A take to do it alone?
A, B, and C can do a piece of work in 6 days, 12 days, and 24 days respectively. In what time will they altogether do it?
A and B working together can mow a field in 56 days and with the help of C, they could have mowed it in 42 days. How long would C take by himself?
A can do a piece of work in 24 days, A and B can do it in 16 days and A, B, and C in `10 2/3` days. In how many days can A and C do it working together?
P alone can do `1/2` of a work in 6 days and Q alone can do `2/3` of the same work in 4 days. in how many days will they finish `3/4` of the work, working together?
