Question

If the nth of the a sequence is 4$n^{2}$-5 then the 50th term of this sequence is
A) 9985
B) 9990
C) 9995
D) 10000

Answer 1

Topic :- Sequence and Series

Given :- nth term of sequence is 4n² - 5.

To Find :- 50th term of the sequence.

Solution :-

nth term of sequence = 4n² - 5

If we want to calculate the value of 50th term then we will have to put the value of n = 50.

Putting n = 50,

50th term of sequence = 4(50)² - 5

50th term of sequence = 4(2500) - 5

50th term of sequence = 10000 - 5

50th term of sequence = 9995

So, 50th term of the sequence is 9995.

Answer :-

So, the 50th term of the sequence is 9995 which is option C.

Additional Information :-

Arithmetic Progression

A sequence with common difference between its consecutive terms.

For example,

2, 5, 8, 11, . . . . .

40, 30, 20, 10, . . . .

Geometric Progression

A sequence with common ratio between its consecutive terms.

For example,

2, 4, 8, 16, 32, . . .

5, 10, 20, 40, . . .