a) In my opinion no, because all the measures are different.
b) 3 blue paint : 1 yellow paint = green paint Gpe
6 parts blue : 2 parts of yellow = Asura
Yes, the green paint will be the same because
3/1 = 3 and 6/2 = 3
In both cases the relationship is 3.
c) Saraya = 650 / 10 min = 65 words/min
Rashid = 780/12 min = 65 words/min
Yes, they write at the same speed because in both the speed is 65 words/mn