This problem is an
example of ratio and proportion. A ratio is a comparison between two different
things. For 3:8, it does not coincide with the ratio 40:15. If we try to
multiply 3 by 13, it would not reach 40. Same thing goes for 8 multiplied by
13. For 8:3, if we try to multiply 8 by 5 we would get 40. If we also multiply
3 by 5 we would get 15. Therefore b. is proportional to 40:15. For 90:240, if
we multiply 40 by 2, we would not get 90, also in 15, we would ot get 240. For 120:45,
if we multiply 40 by 3 we get 120. Also, if we multiply 15 by 3 we would get
45. Therefore, d is also proportional to 40:15.
