Question

A biased 3-coloured spinner was spun 240 times. It landed on Red n times, on Orange 3n times and on Yellow 8n times.

If you spin this spinner 1000 times, how many times do you expect it to land on Red?
(Hint: Find n first)

Answer 1

83 times.

Explanation:

n + 3n + 8n = 240

12n = 240

n = 20.

So we have 20 reds in 240 spins

So by proportion the number expected in 1000 spins

= 20 * 1000/240

= 1000/12

= 83 1/3

So its 83 reds.