A chicken weighs t lbs. It needs to be cooked for 20 minutes per lb plus an extra 15 minutes. What is the total cooking time? Is this the correct written expression: 15t + 20? Why or why not?

Total cooking time = 20t + 15

The expression 15t + 20 is wrong.

Step-by-step explanation:

weight of chicken = t lbs

cook time per lb = 20 minutes

This means that:

1 lb weight requires a cooking time of 20 minutes

1 lb = 20 minutes

∴ t lbs = 20 * t = 20t minutes.

We were also told that each chicken required an extra cooking time of 15 minutes, in addition to the total cooking time due to the weight. Therefore, the total cooking time is calculated thus:

Total cooking time = cooking time due to weight + 15 minutes

Total cooking time = 20t + 15

Hence the expression 15t + 20 is wrong, due to the explanation given above.