SOLUTION: When 1/5 of the boys left, there were still b boys and g girls who stayed to see the end of the program. What was the total number of boys and girls at the beginning of the progra

The problem doesn't say that any girls left, so we'll assume that no girls
left, and so there were also g girls at the beginning of the program.

Let x = the number of boys at the beginning of the program.

Then we subtract one-fifth of x from x to get b boys: 



Multiply through by 5:







Checking:
There were  boys at the beginning, then  left,
and so there were  boys at the end.

Answer:  boys and g girls at the beginning.

Edwin