The mean weight of females in a class is 60kg and that of the males is 72kg. If the mean

weight of the class is 68kg, what is the ratio of females to males in the class?

1:2

Step-by-step explanation:

Let's say there are x males and y females in the class.

The sum of all male weights will be 72x, and the sum of all female weights will be 60y.

If we get a class mean weight, we have:

(72x + 60y) / (x+y) = 68

72x + 60y = 68x + 68y

4x = 8y

y / x = 4/8 = 1/2

So the ratio of females to males is the class is 1:2

the answer would be d

straight away you can eliminate a and c because not all books contain a scientific skill because some may be fiction. c is also wrong because it saids that the only way children can learn is through books which is incorrect.

b is also wrong because reading can be a scientific skill but not always, therefore it is wrong which leaves you with d, the correct answer since it said that it can children learn.

hope this ! : 3