Question

A bad contains 7 red marbels and 4 blue marbles

A marble is taken from the bag and replaced
another marble is taken from the bag

Work out the probability that the two marbles are the same colour
Give your answer as a fraction

Answer 1

Explanation:

(a) Because there are 7 red and 4 blue marbles, there are 7+4=11 marbles in the bag.

So the ratio of all marbles to blue marbles is 11 to 4.

We write this as follows. 11:4

(b)There are 7 red marbles and 4 blue marbles in the bag.

So the ratio of red marbles to blue marbles is 7 to 4.

We write this as follows. 7:4

Answer 2

I think its 7/3 or 6/4

Explanation: