Number series and patterns
Commercial arithmetic · Mathematics
Study notes
Q: Find the 10th term and sum of first 10 terms of 3, 7, 11, 15... Step 1: This is AP with a = 3, d = 4. Step 2: 10th term = a + 9d = 3 + 36 = 39. Step 3: Sum = n/2 * (2a + (n-1)d) = 10/2 * (6 + 36) = 5 * 42 = 210.