Multiple choice

What is the 90th term of the given sequence? 1, 4, 7, ...

  1. 268

  2. 254

  3. 244

  4. 243
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sequence is arithmetic with a first term a = 1 and a common difference d = 3. The formula for the n-th term is a + (n - 1)d. For n = 90, the term is 1 + (89 * 3) = 1 + 267 = 268.

AI explanation

Using the formula for the nth term of an arithmetic progression, a_n = a + (n - 1)d, where a is 1 and d is 3. The 90th term is 1 + (90 - 1) * 3 = 1 + 89 * 3. This calculates to 1 + 267 = 268.

Keep practicing — related questions