What is 1 and a half plus 3 quarters?

Addition of fractions.

1 1/2 + 3/4

First convert to improper fractions.

3/2 + 3/4

Secondly, bring to a common denominator of '4' and equivalent numerator

6/4 + 3/4

Add the numerators

9/4

Bring back to a mixed number.

9/4 = 2 1/4 (The Answer!!!!)