3/4+2/5 is 1 and 3/20 because first, you have to find the common denominator, which is 29. Next you have to multiply the numerator by the number that you multiplied the denominator by. You will then get 15/20+8/20. Next you add 15+8, which is 23. Then you get 23/30, which you then simplify to 1 and 3/20.