Business Math help please, Brownies

Question

Bought 20 unit of brownies cost $.79

Total cost ?

Percent markup 60%

Total selling price ?

Percent that will spoil 10%

Selling price per brownie ?

Answer 1

20*$0.79=$15.80 total cost

60%=0.6, 100%=1, 1.6*$15.80=$25.28 total selling price

10%*20=0.1*20=2 brownies spoil which leaves 18 brownies to sell

$25.28/18=$1.40444... so you sell the brownies for either $1.40 or $1.41 each

18*$1.40=$25.20 so you lose $0.08 altogether

18*$1.41=$25.38 so you make an extra $0.10 altogether