Which is best to buy
a( 16 ounces of hand soap for $2.40
b( 20 ounces of hand soap for $2.80
c( 24 ounces of hand soup for $3.00
d( 12 ounces of hand soup for $2.00

So assuming you want the most units of stuff for the smasllest units of cost
make into fractions and simplify
money per unit of stuff
cost per unit

so we do
A. 16 oz for 2.40
2.4/16=0.15/1

B. 20 oz for 2.80
2.8/20=0.14

C. 24 oz foe 3
3/24=0.125

D. 12 for 2
2/12=0.167

find smallest cost per unnit

answe ris 0.125
answer is C. 24 oz for 3 dollar