Answer:
Use 49 ounces of the 14% allow and 41 ounces of the 23% alloy.
Step-by-step explanation:
Each ounce of the 14% copper contains 0.14 ounce of pure copper.
Each ounce of the 23% copper contains 0.23 ounce of pure copper.
Each ounce of the 18.1% copper contains 0.181 ounce of pure copper.
Use x ounces of the 14% and y ounces of the 23% to make 90 ounces of 18.1% alloy.
x+y = 90
y = 90-x
0.14x + 0.23y = 0.181·90
0.14x + 0.23(90-x) = 16.29
0.14x + 20.7 - 0.23x = 16.29
-0.09x + 20.7 = 16.29
4.41 = 0.09x
x = 49
y = 90-x = 41
Use 49 ounces of the 14% allow and 41 ounces of the 23% alloy.
Can you tell us what the expression is in the question?
<u><em>Answer:</em></u>
The sales tax is 8%
<u><em>Explanation:</em></u>
<u>We are given that:</u>
The price of the rocket is $24 and the sales tax is $1.92
To get the percentage of the sales tax, all we have to do is divide the sales tax by the price of the rocket and then multiply the quotient by 100 (to convert the ratio to percentage)
<u>This is done as follows:</u>
% of sales tax = 
% of sales tax = 
%
Hope this helps :)
9: the answer is 4 to 13
10: the answer is 6 to 13
