Question

4 mark please help me

Answer 1

Explanation:

a probability is always desired cases / total cases.

from the table and given information we know :

there are 40 blue counters.

0.25 = 40/x

x being the total number of counters in the box.

x = 40 / 0.25 = 160

the sum of all probabilities must be 1 (the always true probability), as there are only counters in the box, and one of the 4 colors is always the result.

so,

1 = 0.25 + 0.35 + 0.3 + red-probability

1 = 0.9 + red-probability

red-probability = 1 - 0.9 = 0.1

0.1 = red counters / 160

red counters = 0.1 × 160 = 16

there are 16 red counters in the box.

Answer 2

There are 4 red counters

Explanation:

1. Add the known decimals

`0.25+0.35+0.3=0.9`

2. Subtract that amount from one

`1-0.9=0.1`

3. multiply the result by 40

`(40)(0.1)=4`

Hope this helps