There were 80 more boys than girls in a club. 10% of the boys went for a camp and the remaining number of pupils in the club became 1402 pupils. How many girls were there in the club?

1. Express the number of remaining boys and girls in terms of a variable

Let the number of girls be $x$.
The number of boys is $x + 80$.
Since $10\%$ of the boys went for a camp, the remaining percentage of boys is $100\% - 10\% = 90\%$.
Number of remaining boys = $0.9(x + 80) = 0.9x + 72$.
The number of girls remains $x$.

2. Form an equation for the total remaining pupils and solve for $x$

Total remaining pupils = Girls + Remaining boys
$x + 0.9x + 72 = 1402$
$1.9x + 72 = 1402$
$1.9x = 1402 - 72$
$1.9x = 1330$
$x = \frac{1330}{1.9} = 700$