Question

9. 6th term from the end of the sequence 9, 12, 15 20th term is (a) 50 (b) 52 (c) 51 (d) 55 10 Teth​

Answer 1

Answer:

50

Step-by-step explanation:

9,12,15,20,26,33,41,50

Answer 2

Given: The sequence 9, 12, 15,...

To find: The 6th term from the end of the sequence.

Solution:

• The 6th term from the end of a sequence with 20 terms is the 15th term.
• The sequence given is an arithmetic sequence, so there is a common difference between the consecutive terms.
• A certain term of an arithmetic sequence is calculated using the formula,

        $t_{n} = a + (n-1)d$

• Here, n is the term to be found,  $t_{n}$ is the value of the term to be found, a is the first term and d is the common difference.
• In the given question, the first term is 9 and the common difference is 3.
• On replacing the terms with the values given in the question,

        $t_{15} = 9 + (15-1)(3)$

              $= 51$

Therefore, the 6th term from the end of the given sequence is 51.