.
Solution 1
Let d be the distance between the cities A and B.
Terence' traveled time was 4 hours (from noon till 4pm).
Hence, Terence' average speed was hours.
It means that the Linda's average speed was km/h (15 km/h slower than that of Terence).
In 4 hours, from noon till 4 pm, Linda covered 224 kilometers.
It gives you this equation
= 224, or
= = 56.
Multiply both sides by 4 to get
d - 60 = 56*4 = 224
d = 224 + 60 = 284.
ANSWER. The distance between the cities is 284 km.
Solved.
Solution 2
Another way to solve this problem is to write so called "speed equation"
- = 15
Saying that the difference between two speeds, and is 15 km/h.
Then from the equation you get
- 56 = 15,
= 15 + 56 = 71,
d = 4*71 = 284,
giving the same answer.
Solution 3
In this way, you even may solve the problem MENTALLY, without using equations.
The average speed of Linda is = 56 km/h.
The average speed of Terence is 15 km/h faster, i.e. 56+15 = 71 km/h.
Then the distance from A to B, which Terence covers in 4 hours, is 71*4 = 284 kilometers.
It is the same solution as in Version #2 in this post, simply presented in wording form.