Answer:
6.5%
Step-by-step explanation:
If you take 31.20 and divide it by 480, you get .065, which would then be converted into percentages by multiplying it by 100 (6.5%).
Since there are

in a circle, and central

, you can see that the part "sliced out" by the central angle is

of the whole circle.
This means that the length of the intercepted arc

is

of the circumference of the circle. So,
Answer:
$40
Step-by-step explanation:
x is the original price of the gift
(10% of x) is the value of the discount
(10% of x) = 10/100 . x = 0.1 x
0.1 x is the value of the discount
x - (10% of x) is what was paid, after the discount
x - 0.1 x = 0.9 x
0.9 x is what was paid
4 children paid $9/each
4 times $9 = $36
$36 is the total amount that was paid by the children
$36 = 0.9 x
$36 / 0.9 = x
x = $36 / 0.9 = 360 / 9
x = 40
;-)