Problema Solution
Tina and Bruce each have a 1to 6 number cube. They are looking for different ways to roll two factors whose product is greater than 14. How many ways will they find
Answer provided by our tutors
let
x = the number that Tina rolls
y = the number that Bruce rolls
x, y are elements of the set {1,2,3,4,5,6} thus x < 7 and y < 7
also we need x* y > 14
from
x* y > 14 and 7>y we have
7*x > 14
x > 2
we have the following cases
x = 3
3,5
3,6
x = 4
4,4
4,5
4,5
x = 5
5,3
5,4
5,5
5,6
x = 6
6,3
6,4
6,5
6,6
there are 2 + 3 + 4 + 4 = 13 ways to do the rolling.