Question

Can u explain the answer of c)ii)plss:(​

Answer 1

Answer:

i) The probability of getting 50 cent coin is 5/18, or approximately 28%

ii) To scale the numbers up to let us have 65 fifty cent coins, there would be a total of 234 coins

Step-by-step explanation:

We are told the probability of choosing ten and 20 cent coins, and from that we can work out the probability for the 50 cent coin.  All we need to do is add up the other two probabilities and subtract them from 1.

$p = 1 - (\frac{1}{3} + \frac{7}{18})\\p = 1 - (\frac{6}{18} + \frac{7}{18})\\p = 1 - \frac{13}{18}\\p = \frac{5}{18}$

So the chance of getting a 50 cent coin is five eighteenths, or approximately 28%

For the second question We are asked to find the total number of coins if there are 65 fifty cent coins. (I can't see the text below that, but presumably it's saying that the ratios will stay the same).

We can solve this by comparing the two ratios, with x as the total, and solving for x:

$\frac{5}{18} = \frac{65}{x}\\5x = 65 * 18\\x = 13 * 18\\x = 234$

So to keep the same ratios and have 65 fifty cent coins, we would need a total of 234 coins.