Carcass wrote:
x is a non-negative integer less than 7 and y is a non-positive integer greater than -4. For how many cases is the sum of x and y less than 5?
A. 0
B. 9
C. 16
D. 23
E. 25
x is a non-negative integer less than 7Possible values of x: 0, 1, 2, 3, 4, 5, 6
y is a non-positive integer greater than -4Possible values of y: 0, -1, -2, -3
For how many cases is the sum of x and y less than 5?Let's individually examine each possible value of y and determine the number of x-values that go to yield a sum that is less than 5.
If y = 0, then x can equal 0 to 4 inclusive (
5 values)
If y = -1, then x can equal 0 to 5 inclusive (
6 values)
If y = -2, then x can equal 0 to 6 inclusive (
7 values)
If y = -3, then x can equal 0 to 6 inclusive (
7 values)
So, the total number of cases:
5 +
6 +
7 +
7 =
25Answer: E