Answer:
50 miles per hour
Step-by-step explanation:
50 miles matches up with 1 hour, 100 miles matches up with 2 hours, and so on.
Hope this helps! :)
You are right on the question
Use the Pythagoras' Theorem:
A^2 + B^2 = C^2
20^2 + 35^2 = C^2
400+ 1225=1625=C^2
square root of 1625= C = 40.31 km
Let

be any integer. Then

In other words:
(1) If

is a multiple of 4, then

.
(2) If dividing

by 4 leaves a remainder of 1, then

, since

for some integer

, and from (1) we know that

(because, obviously,

is a multiple of 4).
(3) If instead you get a remainder of 2, then

. This follows from (1) as well.

.
(4) Finally, if you get a remainder of 3, then

.