19/12 or 1 and 7/12 ........

First, you have to find the least common denominator which woukd be 12. Bith 3 and 4 go into 12. 1/3 becomes 4/12 (3×4=12 and 1×4=4) and 5/4 becomes 15/12 (4×3=12 and 5×3=15). 4/12 + 15/12 = 19/12 which equals 1 and 7/12.