Question 989097

My daughter got this question wrong and asked me to see why. When I tried to work the problem out myself, my answer of $719.90 was not listed as correct either. I tried 2/3 + 1/8 = 19/24, convert to .792 then .792 * 3461.04 = 2741.14 and subtract from $3461.04. The correct answer was listed as $721.05. I guess my question is what is the correct way to write out this problem and solve (rounded to the nearest cent per directions). 

Patti's monthly pay is $3461.04. Each month she uses 2/3 of her pay for her household expenses and 1/8 for entertainment. She deposits the rest into her savings account. How much does Patti deposit into her savings account each month?

Any help would be greatly appreciated. 

Sol'n

3461.04*(1-(2/3)-(1/8))
$721.05
<pre>Since she uses {{{2/3}}} for household expenses and {{{1/8}}} for entertainment, she uses a total of {{{2/3 + 1/8}}}, or {{{16/24 + 3/24}}}, or {{{19/24}}}.
Thus she has {{{1 - 19/24}}}, or {{{5/24}}} left, so she deposits {{{5/24}}} of $3,461.04, or {{{5("$"144.21)}}}, or {{{highlight_green("$"721.05)}}} in her savings account. 
It's best sometimes to work these problems step-by-step, so there's less of a chance to make an error. 
Your mistake was converting the fraction of what she spent ({{{19/24}}}) to a decimal, which you ROUNDED OFF. 
As you see your answer was off, so you can't do this.