Question
Find the sum:
$25 + 28 + 31 + ..... + 100.$
$25 + 28 + 31 + ..... + 100.$
✓
Answer
$25 + 28 + 31 + ..... + 100$
$a = 25, d = 3, l = a_n = 100$
$100 = 25 + (n - 1) \times 3$
$75 = (n - 1) \times 3$
$n - 1 = 25$
$n = 26.$
$a = 25, d = 3, l = a_n = 100$
$100 = 25 + (n - 1) \times 3$
$75 = (n - 1) \times 3$
$n - 1 = 25$
$n = 26.$
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