Higher November 2017 Paper 2 Q4
4 There are only blue cubes, yellow cubes and green cubes in a bag.
There are
twice as many blue cubes as yellow cubes
and four times as many green cubes as blue cubes.
Hannah takes at random a cube from the bag.
Work out the probability that Hannah takes a yellow cube. (3)
| Answer | Mark | Notes |
|---|---|---|
| \(\dfrac{1}{11}\) | P1 | for starting the process, eg by writing down a correct ratio or using a given number of cubes for one relationship, eg 2B 1Y or B:Y = 2:1 or 4G 1B or G:B = 4:1 or 8G, 1Y or G:Y = 8:1 oe or yellow = 2, blue = 4, or states 2:1:8 oe in any order (can be algebraic) |
| P1 | for complete process to find possible number of each colour or equivalent ratio, eg 8G 2B 1Y or G:B:Y = 8:2:1 oe or yellow = 2, blue = 4, green = 16 oe (can be algebraic) | |
| A1 | \(\dfrac{1}{11}\) oe |