Half is 1/2. 11+2 = 1/31+3 =1/41+4 =1/5 (. Solution: Let's plant X trees. 1/3x+ 1/4x+ 1/5x+ 13 = x47/60x+ 13 = x47/60x = x- 13 x-47/60x = 13 13 13/60x = 13 = 65438。 . . They planted 60 trees at a time. Look at yourself, right or wrong is not necessarily.