Every evening Jenna empties her pockets and her change in a jar. At the end of the week she counts all her money. One week she had 50 coins, all of them dimes and quarters. When she added them up, she had a total of $10.25.
How many dimes did she have?

Question

Every evening Jenna empties her pockets and her change in a jar.  At the end of the week she counts all her money.  One week she had 50 coins, all of them dimes and quarters. When she added them up, she had a total of $10.25.
How many dimes did she have?

luckycoins888 · Answer

let d be the number of dimes 
let q be the number of quarters 

d + q = 40------> multiply this by -25 
10d + 25q = 775 


-25d -25q = -1000 
10d +25q = 775 
----------------------------- 
-15d = -225 
d = 15 dimes


@atlantaslast There you go XD