Problem:
In the expression (____ × ____) + (____ × ____) each blank is to be filled in with one of the digits or , with each digit being used once. How many different values can be obtained?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Both the multiplications and the addition can be performed in either order, so each possible value can be obtained by putting the 1 in the first position and one of the other three numbers in the second position. Therefore the only possible values are
so just different values can be obtained.
The problems on this page are the property of the MAA's American Mathematics Competitions