1.
Suppose a1,a2,,an,a_1, a_2, \dots, a_n, \dots is an arithmetic progression of natural numbers. If the ratio of the sum of the first five terms to the sum of the first nine terms of the progression is 5:175:17 and 110<a15<120110 < a_{15} < 120, then the sum of the first ten terms of the progression is equal to: