Sch A : B+G=642Sniper Angel wrote:There are 642 pupils in School A and 840 pupils in School B. The number of boys in both schools is the same.Given that the number of girls in School B is four times that of School A, find the total number of boys in each school.

Sch B : B+4G=840

B+4(642-B)=840

3B=1728

B=576 for both school

Now I m worry..is the above method acceptable? Or must use the modelling method (with unit)? The marks will be on the final answer only or workings will also get marks?