Answer :
With the new ratio
3 maple trees for every 11 oak trees
132 oak trees (11*12=132)
3*12 = 36 maple trees
36 maple trees plus 132 oak trees = 168 total trees
since your original ratio was 9:5 that means 9/14 of the trees were maple; so set up a proportion to find the number of trees that were maple before the bugs
[tex] \frac{9}{14}= \frac{x}{168} [/tex] cross multiply
14x = 1512
x= 108 maple trees before there were bugs
Finally do 108 - 36 (maple trees before, minus, maple trees after)
difference = 78 maple trees
3 maple trees for every 11 oak trees
132 oak trees (11*12=132)
3*12 = 36 maple trees
36 maple trees plus 132 oak trees = 168 total trees
since your original ratio was 9:5 that means 9/14 of the trees were maple; so set up a proportion to find the number of trees that were maple before the bugs
[tex] \frac{9}{14}= \frac{x}{168} [/tex] cross multiply
14x = 1512
x= 108 maple trees before there were bugs
Finally do 108 - 36 (maple trees before, minus, maple trees after)
difference = 78 maple trees