Question

8. A and B can finish a piece of work in 16 days and 12 days respectively. A started the work
and worked at it for 2 days. He was then joined by B. Find the total time taken to finish the work?
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Answer 1

Given that A finishes the work in 16 days.

A finishes 1/16 of the work in one day.

A had worked for two days= 2*1/16 = 1/8

the work left after A has worked for two days = 1- 1/8 = 7/8

B finihses the work in 12 days

in 1 day B finishes 1/12 of the work.

A and B togeher in one day can finish= 1/16+1/12 = (3+4)/48= 7/48 of work

A and B together can complete the remaining work= (7/8) / (7/48)= 7*48/8*7 = 6 days.

therefore total time taken = 2 days by A alone + 6 days by both Aand B = 8 days

Answer 2

☆$\red {HELLO\:DEAR}$☆

Average work=48(LCM of 16 and 12)

A does 48 work in 16 days

In 1 day 48/16=3work

B does 48 work in 12 days

In 1 day 48/12=4work

A done work for 2 days

So,work done by A 8n 2 days=2×3=6

Remaining work is 42

A+B together can do 7 work in a day

Thus,42/7=6days

Total days 6+2=8days.

☆$\green {VISHU\:PANDAT}$☆

☆$\blue {FOLLOW\:ME}$☆