Given a + 10d = 38 and a + 15d = 73, subtracting gives 5d = 35, so d = 7 and a = -32. Using tn = a + (n – 1)d, the 31st term is -32 + 30 x 7 = 178.
Share
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Let a be the first term and d be the common difference.
Given:
11th term: t11 = a + 10d = 38
16th term: t16 = a + 15d = 73
Subtracting the first equation from the second:
(a + 15d) – (a + 10d) = 73 – 38
5d = 35
d = 7.
Substituting d = 7 into the first equation:
a + 10 x 7 = 38
a + 70 = 38
a = 38 – 70 = -32.
Now, finding the 31st term:
t31 = a + 30d = -32 + 30 x 7 = -32 + 210 = 178.
Hence, the 31st term is 178.
For more NCERT Solutions of Class 9 Ganita Manjari Chapter 8 Predicting What Comes Next: Exploring Sequences and Progressions Question Answer (2026-27)
https://www.tiwariacademy.com/ncert-solutions/class-9/maths/ganita-manjari-chapter-8/