What is 2 and 3 4ths plus 1 and 1 half?

To add 2 and 3/4 plus 1 and 1/2, first convert the mixed numbers to improper fractions. 2 and 3/4 becomes 11/4, and 1 and 1/2 becomes 3/2, which is 6/4 when expressed with a common denominator. Adding these gives you 11/4 + 6/4 = 17/4, which can be converted back to a mixed number as 4 and 1/4.