Question

if 3boy or 6girls do a piece of work in 6/5 hours so 1boy and 1 girl do this work in how many hours

Answer 1

It is a case of inverse proportion,so

For Boys

3 boys — 6/5hours
1 boy — x hours

In inverse proportion following happens
(Hopefully u know)

3*1 = 6/5*x
x = 3*5/6
x = 15/6hrs

For Girls

6 girls—6/5hours
1 girl—y hours

So,
6*1 = 6/5*x
x = 30/5
x = 6hrs