Joshua delivered 30 hives for the farmer which are 5% of the total number of Joshua's hives. In other words, 30 hives are 5% of an uknown number:
30 = 5% from x
30 = 5/100 x / * 100 (both sides)
3000 = 5x / ÷ 5 (both sides)
x = 600
Answer: Joshua has 600 hives in all.