Answer:
a:b:c=8:12:15
Explanation:
Combined Ratio
We are given the ratios:
a:b=2:3
b:c=4:5
The combined ratio a:b:c will include all three variables in one single expression.
Before finding it, we must have a common number for the common variable (b). Since b is 3 in the first ratio and 4 in the second ratio, we must equate both by finding the LCM of 3 and 4=12, thus both ratios will be amplified as follows:
a:b=2:3=(2*4):(3*4)=8:12
b:c=4:5=(4*3):(5*3)=12:15
Now there is a common factor in both ratios, we can combine them removing the common factor:
a:b:c=8:12:15