Answer:
Number of times would Lewis be expected to roll a multiple of 3 = 75
Step-by-step explanation:
Multiples of 3 in 1 to 10 are 3,6 and 9
So we are having 3 multiples of 3 in 1-10
Probability of an event is the ratio of number of favorable outcome to the total number of outcomes.
Probability to roll a multiple of 3 
Total number of rolling = 250
Based on the theoretical probability, number of times would Lewis be expected to roll a multiple of 3 = Total number of rolling x Probability to roll a multiple of 3
Number of times would Lewis be expected to roll a multiple of 3 