Question 220194
An eighth grade class picnic has a boy-girl ratio of 5:3.
 Three more girls join the class, changing the ratio to 10:7. How many students are now in the class?
:
Let m = the multiplier
:
{{{(5m)/(3m+3)}}} = {{{(10)/(7)}}}
Cross multiply
7(5m) = 10(3m+3)
35m = 30m + 30
35m - 30m = 30
5m = 30
m = {{{30/5}}}
m = 6 is the multiplier
:
Find the no. of girls now
girls = 3(6) + 3
girls = 21 girls
:
:
Check solution
6*5 = 30 boys
:
30/21 = 10/7