Question: If the 1st term of an arithmetic progression is 4 and the common difference is 3, what is the sum of the first 10 terms?
Options:
Correct Answer: 80
Solution:
The sum of the first n terms S_n = n/2 * (2a + (n-1)d). Here, S_10 = 10/2 * (2*4 + 9*3) = 5 * (8 + 27) = 5 * 35 = 175.