Question

A truck that can carry no more than 7600 lb is being used to transport refrigerators and upright pianos. Each refrigerator weighs 300 lb and each piano weighs 525 lb. Write and graph an inequality to show how many refrigerators and how many pianos the truck could carry. Will 13 refrigerators and 7 pianos overload the​ truck? Explain.

Answer 1

Explanation:

Represent the number of refrigerators by r and that of pianos by p.

Then the total weight in the truck bed is calculated and we determine whether or not this total is less than the truck capacity.

Find the total weight of the load consisting of 13 refrigerators and 7 pianos. The inequality given above becomes:

w(r, p) = (300 lb)r + (525 lb)p ≤ 7600 lb

w(13, 7) = (300 lb)13 + (525 lb)7 ≤ 7600 lb becomes:

w(13, 7) = 3900 lb + 3675 lb = 7575 lb

Since 7575 lb is just under the truck's capacity (7600 lb), the truck will not be overloaded.

Answer 2

13 refrigerators and 7 pianos will NOT overload the truck

Explanation:

For x refrigerators, their total weight is 300x.

For y pianos, their total weight is 525y.

The total weight of both of these together must not exceed 7600, so the inequality is ...

300x +525y ≤ 7600

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The point (x, y) = (13, 7) lies in the solution area. The truck will not be overloaded.

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Check

300(13) +525(7) = 7575 . . . this is less than 7600