Multiple choice

Find the 15th term of the sequence 20, 15, 10

  1. -50

  2. -55

  3. -40

  4. -30

  5. -70
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A Correct answer
Explanation

This is an arithmetic progression with first term a = 20 and common difference d = -5. The 15th term is a + (15-1)d = 20 + 14(-5) = 20 - 70 = -50.

AI explanation

This sequence is an arithmetic progression with the first term a as 20 and the common difference d as -5. Using the formula for the nth term, Tn = a + (n - 1)d, we calculate the 15th term as 20 + (15 - 1)(-5). This simplifies to 20 minus 70, resulting in -50.

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