Jan walks 2 miles at a constant rate of 3 miles per hour and then runs 1 mile at a constant rate of 8 miles per hour. (a) What is Jan’s average speed for the entire trip?
(b) Is the average speed in part (a) equal to the average of Jan’s two speeds?

(a).4.36 mph

(b) No

Step-by-step explanation:

We are given that

Jan covered distance,s1 =2 miles

Speed of Jan, a=3 mph

s2=1 mile

b=8mph

a.

We have to find the Jan' s average speed for the entire trip.

Average speed =

Using the formula

Average speed=

b.

Average speed with two speed

Average of Jan’s two speeds

=

Hence, the average speed in part (a) is not equal to the average of Jan’s two speeds.

let x be the money she spent so that she can earn the free t-shirt.

since, she already spent $112.49

⇒

also, as per the statement: jennifer must spend $250 or more in order to qualify for a free t-shirt at the store.

then,

we have an inequality i.,e

subtract 112.49 from both sides we get;

therefore, $137. 51 more money does jennifer need to spend so that she can earn the free t-shirt