A and B can together finish a work in 30 days. they worked at it for 20 days and then B left. the remaining work ws done by A alone in 20 more days. A alone can finish the work in :

A and B can do a piece of work in 45 days and 40 days respectively. They began to do the work together but A leaves after some days and then B completed the remaining work in 23 days. The number of days after which A left the work was

Answer:D Explanation:(A+B)’s 1 day’s work =[ 1 45 + 1 40 ]= 17 360 ⇒ Work done by B in 23 days=1× 23 40 = 23 40 ⇒ Remaining work =1− 23 40 = 17 40 ⇒ Now, 17 360 work was done by (A+B) in 1 day. ⇒ 17 40 work was done by (A+B) in 1× 360 17 × 17 40 =9 days. Therefore, A left after 9 days.

A and B can do a piece of work in 45 days and 40 days respectively. They began to do the work together but A leaves after some days and then B completed the remaining work in 23 days. The number of days after which A left the work was

Answer:D Explanation:(A+B)’s 1 day’s work =[ 1 45 + 1 40 ]= 17 360 ⇒ Work done by B in 23 days=1× 23 40 = 23 40 ⇒ Remaining work =1− 23 40 = 17 40 ⇒ Now, 17 360 work was done by (A+B) in 1 day. ⇒ 17 40 work was done by (A+B) in 1× 360 17 × 17 40 =9 days. Therefore, A left after 9 days.

Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank in gallons is

Answer:B Explanation:Let's calculate how much time it takes to repair the road if just 1 person were working on it. 5 hours a day for 12 days makes it 60 hours per person. 39 people working 60 hours each makes it 39×60=2340 hours in total. Now we have 30 people working 6 hours a day ⇒ That means 30×6=180 hours are spent each day. We need a total of 2340 hours. With 180 hours every day, that's going to take 2340 180 = 13 days to complete... Or you could just do it in one step... :) 39×12×5=30×x×6 2340=180x x= 2340 180 x = 13.