Begin by multiplying $15.65 by 0.20 to find what 20% of the regular price is. This gives you 3.13, which in this situation means $3.13.
To find the price with discount subtract 15.65-3.13. This gives you $12.52.
To find out the change, subtract 20-12.52. This gives you $7.48.
So, he will receive $7.48 in change.
Hope this helps!
Circumference of circle = pi*diameter = 13pi cm
Area is pi*d^2/4 = pi*13^2/4 = 42.25pi cm^2.
