Question
A bag contains 50 counters.
10 of the counters are red.
One of the counters is taken from the bag at random.
(a) Draw an arrow (↓ ) on the scale to show the probability that this counter is red.
(b) Find the probability that the counter is not red.
Answer/Explanation
(a) Arrow at 0.2
(b) 0.8
Question
A bag contains red marbles, green marbles and blue marbles only.
The ratio of the number of marbles of each colour is
red : green : blue = 12 : 5 : 2.
There are 112 more red marbles than green marbles.
Work out the number of blue marbles.
Answer/Explanation
32