A shopowner blends three types of tea, A, B, Cbin the ratio 6:4:7. If the mass of tea C in the mixture is 28kg, find the difference in the masses of the other two types of tea

7:28 = 4:b = 6:a

you can notice that you multiply 7 by 4 to get 28, so you multiply 4 by 4 to get b and 6 by 4 to get a. or you can say that 7/28 = 4/b and 7/28 = 6/a and solve it the normal way.

b=4*4=16

a=6*4=24

24-16 = 8