Question

Jim has a total of 12 coins. Some of them are nickels, and the others are quarters. If he had 12 more nickels, then the value of the nickels would be the same as the value of the quarters. How many quarters does he have?

Let n = the number of nickels and q = the number of quarters.

Which two equations can be used to solve this problem? Select the two that apply.

Answer 1

`n-\ number\ of\ nickels\\ q-\ number\ of\ quarters\\\\ n+q=12\ \ \ \ | n=12-q\\ 0,05(n+12)=0,25q\\\\ 0,05n+0,6=0,25q\ \ \ | substitute\ n=12-q \\\\ 0,05(12-q)+0,6=0,25q\\\\ 0,6-0,05q+0,6=0,25q\\\\ 1,2-0,05q=0,25q\ \ \ | add\ 0,05q\\\\ 1,2=0,3q\ \ \ | divide\ by\ 1,2\\\\ q=4\\\\ He\ has\ 4\ quarters.`