Answer
The number is 320.
Work Step by Step
step 1
Let x represent the unknown number in the problem.
step 2
"$ 70\%$ of a number" = $\displaystyle \frac{70}{100}\cdot x=0.7x$
" is $224$" is written as " = $224$"
step 3
The equation is
$0.7x=224$
step 4
$0.7x=224\qquad/\div 0.7$
$x=\displaystyle \frac{224}{0.7}=\frac{2240}{7}=320$
The number is $320$.
step 5
Check the solution in the original wording of the problem.
$7$0% of $340,$ ($\displaystyle \frac{70}{100}\cdot 320=224),$
is 224.
OK.
