Help!
Phillip wanted to leave a 15% tip. He thought to himself that 15% = 10% plus half of 10%. Which of the following equations will help Phillip estimate the tip on a $36.00 bill correctly?

A: $3.60 + $1.80 = $5.40
B: $1.80 + $1.80 = $3.60
C: $3.60 + $0.36 = $3.96
D: $3.60 + $3.60 = $7.20