Number of bottles the machine can fill in one hour = 150
Number of bottles machine can fill in ten hours = 150*10 =1500 bottles
Quantity of sunblock in one bottle = 20 oz
Quantity of sunblock in 1500 bottles = 1500 *20 = 30000 oz
Answer : Sally needs at least 30000 oz of sunblock to fill 1500 bottles of sunblock in 10 hours by the machine.