Mathematics
Sequences
अनुक्रम
In this Class 9 Mathematics topic from Sequences and Progressions, students learn how numbers or objects are arranged in a definite order and how to identify the rule connecting successive terms. They practise finding missing terms, writing a sequence from a given pattern, and expressing its general term when the relationship is clear. The topic develops pattern recognition, logical reasoning, and accuracy, while preparing students to understand progressions and solve sequence-based problems in later mathematics.
Practice questions
In the sequence (2,6,12,20,\ldots), (a_n=n(n+1)). Which term is (210)?What will be the (20)th term in the sequence (3,6,10,15,21,\ldots)?In the sequence (1,5,14,30,55,\ldots), the successive differences are (4,9,16,25,\ldots). What will be the next term?What will be the next term in the sequence (2,11,26,47,74,\ldots)?In the sequence (3,4,6,8,12,16,\ldots), two hidden sequences are present. What will be the next term?In the sequence (5,7,14,16,32,34,\ldots), the pattern is add (2) and then multiply by (2). What will be the next term?If (a_1=1) and (a_{n+1}=2a_n+n), what will be (a_5)?If (a_1=4) and (a_{n+1}=a_n+2n+1), what is the value of (a_7)?If (a_n=(-1)^{n+1}n^2), what will be the value of (a_9+a_{10})?In the sequence (1,4,13,40,121,\ldots), each next term is obtained by multiplying the previous term by (3) and adding (1). What is the sixth term?If (a_n=2^n+n), what will be the value of (a_6)?In the sequence (1,3,7,15,31,\ldots), which term is (127)?In the sequence (4,9,16,25,\ldots), which term is (169)?In the sequence (7,12,x,34,51), the differences increase as (5,9,13,17). What is the value of (x)?In the sequence (100,96,89,x,66), the differences are (-4,-7,-10,-13). What will (x) be?In the sequence (2,6,18,54,\ldots), each term is (3) times the previous term. What will be the eighth term?In the sequence (512,256,128,64,\ldots), which is the first term less than (10)?Which of the following sequences is neither an arithmetic progression nor a geometric progression?Which is the correct general term for the sequence (5,12,23,38,57,\ldots)?Which of the following sequences has equal and non-zero second differences between consecutive terms?