Question

A and b undertook to do a piece of work for rs. 4500. a alone could do it in 8 days and b alone in 12 days. with the assistance of c, they finished the work in 4 days. c's share of money is?

Answer 1

a=8
b=12
a+b+c=4
lcm=24
efficiency: a=3,b=2,a+b+c=6
so
c=6-2-3=1
a:b:c=3:2:1=6
1/6×4500=750
is share of c

Answer 2

The money for c is 750 rupees.

Step-by-step explanation:

The number of days taken by A to complete the work alone are:

A=8

The number of days taken by B to complete the work alone are:

b=12

We know that A, B and C finish the work in 4 days. So we have:

a+b+c=4

Taking the lowest common multiple of the three times we have,

lcm=24

We can find the efficiency of the work by dividing the LCM with the time taken. So we have efficiency as:  

ea=3,

eb=2,

e(a+b+c)=6

Which gives us the efficiency of work done by c as:

ec=6-2-3=1

This means that the work done by the three workers is in the ratio

a:b:c=3:2:1

Which means that the value of the work done by c in monetary terms comes out to be:

$\frac{1}{6} \times 4500=750$

So, the share of money given to c is 750 rupees.