Question

A and B can do a piece of work in 5 hours: A and C
in 4 hours; B and C in 3% hours. In what time can
A alone do it?​

Answer 1

Answer:

A will take 18 hours to complete 75 percent of work

Answer 2

Answer:

Step-by-step explanation:

let a,b,c is the work of A,B C in one hour

then

a+b=1/5

a+c=1/4

b+c=1/3       (1)

adding all three

2a+2b+2c=1/5+1/4+1/3

=1/60( 12+15+20)=47/60

2(a+b+c)=47/60

a+b+c=47/120     (2)

subtract (1) from(2)

a=47/120-1/3

=1/120(47-40)

a=7/120

No of hrs

1/a=120/7

Thus A alone  can do the work in 120/7=17.14 hrs