Betty has between 40 and 50 pennies that she wants to arrange in a rectangular array. She
notices she can arrange the pennies in three different ways without any gaps or spaces.
However, if Betty adds two more pennies to her collection, she can only arrange the pennies
in one way without any gaps or spaces: a straight line. How many pennies did Betty
originally have?
Note: An a × b rectangle is considered the same as a b x a rectangle?