There are 10 possible number on the first wheel, their would be 9 possible on the second, 8 on the thrid, 7 on the frouth, and 6 on the fifth.
So, 10 * 9 * 8 * 7 * 6 = 30,240 possible combinations without repeating numbers.
Speed = distance/time
distance = speed * time
let x = time covered by running
15 = run distance + walk distance
15 = 9(x) + 3(3-x)
15 = 9x + 9 - 3x
15 - 9 = 6x
6 = 6x
x = 1 hour
Therefore:
Running distance = speed * time
RD = 9km/hr * 1 hr
RD = 9km
Let n = the unknown number.
Six times a number = 6 * n = 6n
20 more than number = n + 20
Greater than = >
Put it all together:
6n > n + 20
Subtract n from both sides to get constants on one side and variables on the other:
6n - n > 20
5n > 20
Divide both sides by 5 to isolate variable N
n > 4
or (4, ∞)
