3 assembly lines can fill 24 orders in 10 hours , therefore in 1 hour 3 assembly lines can fill 2.4 orders (24/10) , consequently, 1 assembly line can fill 0.8 orders (2.4/3) in 1 hour. Therefore, 7 assembly lines can fill 5.6 (7×0.8)orders in an hour and thus the 7 assembly lines in 5 hours would fill (5.6 ×5)= 28 orders.
Therefore, the answer is 28 orders