For this question here are the formulas,
Let T be the number of 10's
Let F be the number 5's
Let us find the 10's first by this formula.
<span>5(124 - T) + 10T = 840
</span>620-5T + 10T = 840
then
5T = <span>220
</span>5 5
T=44
<span>Now let's find the F using this formula.
</span>
5F + 10T = 840
Sustitute T
5F + 10(44) = 840
<u>5F</u> = <u>400
</u>5 5
F = 80
to Check
F + T = 124
80 + 44 = 124
The correct answer to your problem would be “d”
The answer should be 16 you add 23.96 to both sides
