What you would do is multiply for this problem.
you turn 35% into a decimal so the problem would look like
0.35 x 120 that should equal 42
hope that helps
Let
T---------> <span>the tax rate on the parts in $
we know that
$18.75=$15+$3.50+$T
T=18.75-15-3.5
T=$0.25
so
$3.50----------> 100%
$0.25--------> x
x=0.25*100/3.50------> x=7.14%------> x=7.1%
the answer is
7.1%</span>
When n = 1, 2(1) + 1 = 3
When n = 2, 2(2) + 1 = 5
When n = 3, 2(3) + 1 = 7
When n = 4, 2(4) + 1 = 9
When n = 5, 2(5) + 1 = 11
Sum = 3 + 5 + 7 + 9 + 11 = 35
----------------------------------------------------
Answer: 35
----------------------------------------------------