Answer: 6 by 10 inches
Explanation:
Given: Nash is making a framed enlargement of a Mary Cassatt postage stamp to present to a retired postmaster.
The scale of enlargement is 2 inches to 1 centimeter.
The actual length of the stamp = 3 centimeters
The length of frame =

The actual width of the stamp = 5 centimeters
The width of frame =

Thus, the dimension fo the scale picture is 6 by 10 inches