Question 1075441
<pre>
The 3×5 photo's area is (3 in)×(5 in) = 15 in²
The 5×7 photo's area is (5 in)×(7 in) = 35 in² 

Another way to do it is:

We ask ourselves:

35 is how much more than 15?

To answer that we subtract 35-15 and get 20 more.

Then we ask ourselves:

What percent of 15 is 20?

We divide the "IS" number 20 by the "OF" number 15
and get 1.33..., or  then we change that to a percent.

133.333...% or {{{133&1/3}}}% increase

Either way!

Edwin</pre>