Question 1194190
<br>
Given the ratio 5:4, you can set up a proportion<br>
{{{5/4=30/x}}}<br>
to find the number of $2 coins.<br>
If you solve that by the standard method seen in most textbooks, you would "cross multiply" to get<br>
{{{5x=120}}}
{{{x=120/5=24}}}<br>
A less formal and much easier way to solve the proportion is simply to see that 30 is 6 times 5, so the number of $2 coins is 6 times 4, which is 24.<br>
Finally, you could use formal algebra, starting with the given ratio 5:4<br>
5x = # of $1 coins
4x = # of $2 coins<br>
5x=30
x = 30/5 =6
4x = 4(6) = 24<br>