Question

three brands of cornflakes are available.
brand g: $2.29 for 9 ounces
brand k: $3.79 for 19.4 ounces
brand p: $2.89 for 16.5 ounces

you have a coupon for 20¢ off brand p, and a coupon for 30¢ off brand g. which cereal is the best buy?

Explanation:

Step1: Calculate cost per ounce for Brand G (after coupon)

First, convert the coupon value to dollars: \( 30\cancel{c} = \$0.30 \).
The new price for Brand G: \( \$2.29 - \$0.30 = \$1.99 \).
Cost per ounce: \( \frac{1.99}{9} \approx \$0.221 \) per ounce.

Step2: Calculate cost per ounce for Brand K

No coupon, so use original price: \( \frac{3.79}{19.4} \approx \$0.195 \) per ounce.

Step3: Calculate cost per ounce for Brand P (after coupon)

Convert coupon to dollars: \( 20\cancel{c} = \$0.20 \).
New price for Brand P: \( \$2.89 - \$0.20 = \$2.69 \).
Cost per ounce: \( \frac{2.69}{16.5} \approx \$0.163 \) per ounce.

Step4: Compare the costs per ounce

• Brand G: ~\$0.221/oz
• Brand K: ~\$0.195/oz
• Brand P: ~\$0.163/oz

The lowest cost per ounce is Brand P.

Answer:

Brand P (with the 20¢ coupon) is the best buy, as it has the lowest cost per ounce (\(\approx \$0.163\) per ounce) after applying the coupon.