Multiple choice

Find the sum of first 10 terms of the arithmetic series if $a_1 = 25$ and $a_{10} = 100$.

  1. $300$
  2. $320$
  3. $625$
  4. $312$
Reveal answer Fill a bubble to check yourself
C Correct answer
AI explanation

The sum of an arithmetic series is calculated using the formula $S_n = n/2 \times (a_1 + a_n)$. Substituting the given values into the formula gives $S_{10} = 10/2 \times (25 + 100)$. This simplifies to $5 \times 125$, which equals 625. The result is 625.

Keep practicing — related questions