Question

Lily bought 20.24 pounds of grapefruit. The lightest grapefruit weighed 1.2 pounds. The heaviest grapefruit weighed 1.8 pounds. Which is the best estimate of how many grapefruits she purchased?
A. 40
B. 15
C. 13
D. 8

Answer 1

Given:

• Lily bought 20.24 pounds of grapefruit.
• The lightest grapefruit weighed 1.2 pounds.
• The heaviest grapefruit weighed 1.8 pounds.

To Find:

An estimate of the number of grapefruits she bought.

Answer:

The best estimate is that Lily bought 13 grapefruits.

Step-by-step explanation:

Given that the lightest grapefruit weighed 1.2 pounds and the heaviest one weighed 1.8 pounds, we can take the mean or average of these two weights to estimate the weight of any of the grapefruits that she bought.

That is, we can say that each grapefruit must weigh something close to the average value.

The average can be found as

$\frac{1.2+1.8}{2}=1.5$

Thus, the average grapefruit from the bundle she bought must weigh around 1.5 pounds.

Now, given that the total weight of the grapefruit she bought is 20.24 pounds.

By the Unitary Method,

Weight of One Grapefruit = Total Weight of All Grapefruits ÷ Number of Grapefruits

So, number of grapefruits she bought = Total weight ÷ weight of one grapefruit

In other words,

number of grapefruit = $\frac{20.24}{1.5}=13.49$

Rounding off, we may say that Lily bought 13 grapefruits.