When a group of 50 consecutive multiples of 7 is added the answer is 12 075.

i) What is the smallest of these numbers?
ii) What is the largest of these numbers?

You have a sum of an arithmetic progression, where the common difference is 7.

50/2 (2a+49*7) = 12075
a = 70
70+49*7 = 413

So, numbers range from 70 to 413