my answer is 63.56. i don't know if its right answer. here this problem:
It takes Scott an average of 45 min to prune 1 tree. Victor takes 65 min to prune a tree on average. The Scott-Victor Pruning Service has the contract to prune 92 trees in Flagstaff, AZ. How long will it take them to prune all the trees
rate= rate1+ rate2
rate= 1tree/45min + 1tree/65min= (65+45)/65*45
time= numbertrees/rate= 92(65*45)/110 in minutes, in hours divide by 60. You are wrong.