How many three-digit numbers may be formed using elements from the set {1, 2, 3, 4, 5, 6, 7} if no element may be used more than once in a number and the number must be even?

90

Step-by-step explanation:

set: {1, 2, 3, 4, 5, 6, 7} = 7 numbers | 3 even

no element may be used more than once in a number = distinct elements

and the number must be even = must finish with a even number.

This way, we should start with the last number, which we have 3 possibilities.

Since we have 7 numbers in total, we have 6 options for the first one and then 5 options for the second one.

So, we have 6.5.3 = 90

a

step-by-step explanation:

ca = ec

cpctc makes it so that corresponding parts of the triangle you proved to be equal are equal, the other options aren't part of the part of the triangles you proved to be equal.