Question

A con do a pice of work in 12 days and B can do it in 15 days. in how many days A and B can do tha work?​

Answer 1

Answer:

A and B can do some work in 12 days, B and C in 15 days & C and A in 20 days. If A, B and C are together, how many days will it take to complete?

A + B can do the work in 12 days.

In a single day A+B will do 1/12 th portion of the work.

B+C can do the work in 15 days.

In a single day B+C will do 1/15 th portion of the work.

A + C can do the work in 20 days.

In a single day A+C will do 1/20 th portion of the work.

In a day (A+B)+(A+C)+(C+A) will do=(1/12)+(1/15)+(1/20) portion of the work.

2(A+B+C)=(1/12)+(1/15)+(1/20)=1/5 portion of the work.

Then, (A+B+C) will do =1/10 portion of the work in a day

A+B+C will complete the work in 10 days.

C can finish the portion of the work in a single day = Single day work of (A+B+C)-(A+B)=(1/10)-(1/12)=1/60

So C alone can finish the work in just 60 days.

B can finish the portion of the work in a single day = Single day work of (A+B+C)-(A+C)=(1/10)-(1/20)=1/20

So B alone can finish the work in just 20 days.

A can finish the portion of the work in a single day = Single day work of (A+B+C)-(B+C)=(1/10)-(1/15)=1/30

So A alone can finish the work in just 30 days.