Question

A parcel delivery service charges $2.50 to deliver packages that weigh up to 2 lb. The delivery charge for packages weighing over 2 Ib, but less than 3 1/2 lb, is $2.95, For packages weighing over 3 1/2 lb, but less than 5 lb, the fee is $3.40, and so on. Rosanna uses the service to send a package and is charged $4.75, What is the range of the weight of her package?

Answer 1

range of weight of package is from 8 - 9.5 lbs

Explanation:

Because under 2 lbs is 2.5$ and from 2 - 3.5 lbs is 2.95$ and from 3.5 - 5 lbs is 3.40$.

we can note that

change in number of lbs

3.5lbs-2lbs=1.5lbs

change in rate

2.95-250=0.45

we can clearly see that trend every 1.5 lbs it costs 0.45$ more.

So if we keep following the trend we can conclude that

from 5 - 6.5 lbs the cost would be 3.85$

similarly 6.5 - 8 it would be 4.3$

and

finally

from 8 - 9.5 lbs it would be 4.75$.

hence range of the packet is 8-9.5 lbs

Answer 2

As you can see the trend is that for every 1.5 lbs it costs 0.45$ more. How did we get to know this?

Because under 2 lbs is 2.5$ and from 2 - 3.5 lbs is 2.95$ and from 3.5 - 5 lbs is 3.40$.

So if we keep following the trend we can easily calculate the range. So from 5 - 6.5 lbs it would cost 3.85$ and 6.5 - 8 it would be 4.3$ and from 8 - 9.5 lbs it would be 4.75$. Hence you have your answer.