Problema Solution
when 40% of the girls left the school assembly, the ratio of boys to girls became 3 to 4. if there were w girls when the assembly started what was the total number of boys to girls?
Answer provided by our tutors
w = the number of girls when the assembly started
0.60w = the number of girls after 40% left
x = the number of boys
0.60w : x = 3 : 4
3x = 4*0.60w
x = (4*0.60/3)w
x = 0.80w
The total number of boys to girls was: 0.80w : w = 0.80 = 8/10 = 4/5 or 4 to 5.