Question

The ratio of boys to girls at a summer camp 3:5. If there are 27 boys,how many girls are there ?

Answer 1

Maybe 45 because 3×9=27 and 5×9=45

Answer 2

$g-number\ of\ girls\\\\3:5=\dfrac{3}{5}\\\\The\ equation:\\\\\dfrac{27}{g}=\dfrac{3}{5}\qquad\text{cross multiply}\\\\3g=(27)(5)\qquad\text{divide both sides by 3}\\\\g=(9)(5)\\\\\boxed{g=45}\\\\Answer:\ \boxed{45\ girls}$