Question: A certain arithmetic progression has a first term of 7 and a common difference of 2. What is the sum of the first 10 terms?
Options:
Correct Answer: 75
Solution:
The sum of the first n terms S_n = n/2 * (2a + (n-1)d). Here, S_10 = 10/2 * (2*7 + 9*2) = 5 * (14 + 18) = 5 * 32 = 160.