TEST 1, Q 34
There are 3 bus companies who run services in Chester. One company has 5 blue buses, one has 6 green buses and one has 4 red buses. If one bus from each company were to park at the bus station at the same time, how many possible combinations of buses are there?
OK - start with an easier question .. when I spin two coins they can land:
HH HT TH TT 4 ways ie 2 x 2
Try again - 3 red counters, 2 blue ones:
R1B1 R1B2 R2B1 R2B2 R3B1 R3B2 ie 3 x 2 = 6
If you extend this perhaps you can see why you multiply the number of buses together?
TEST 2, Q 34
The local nursery had some fruit trees that had no labels on them. There were 3 apple trees, 5 pear trees and 4 plum trees. The customers could choose any tree at random. Which of the following have 2 true statements
An even chance means the probablity is more than 1/2 or 0.5
Prob (apple tree) = 3/12 < half
Prob (pear tree) = 5/12 < half
Prob (plum tree) = 4/12 < half
Since I don't know what the other statements are I hope this helps!