Once you find your common denominator (24) you have to do the same to the numerator. So for the roses it would be 9/24 + 8/24 which is 17/24 for both roses and geraniums
Bill's original ratio is like this...
6 to 10
You need to solve for this...
x to 15
You have to multiply both sides of the original ratio by 15...
6 times 15 = 90
10 times 15 = 150
Your new ratio is 90 to 150
Which reduces to 3 to 5
Yout new ratio is 3 to 5
The answer is going to be 15
The answer is 12.2
I calculated it on the calculator
Draw dagarm (see attachment)
we've got a right triangle
the legs are 12 and 15
and the hypohuse is the diagonal
remember, for any right tirnalge
when the legs are a and b and hytponuse is c then
a²+b²=c²
so
12²+15²=c²
144+225=c²
369=c²
sqrt both sides
√369=c
3√41=c
the diagonal is 3√41 m or about 19.2m