if tim had lunch at $ 60.50 and he gave 20 % tip , how much did he spend ?
"the tip is 20 % of what he paid for lunch . hence tip = 20 % of 60.50 = ( 20 / 100 ) * 60.50 = $ 12.1 total spent 60.50 + 12.1 = $ 72.6 correct answer b"
add(60.50, divide(multiply(60.50, 20), const_100))