Question

7,25,61,121, ? a) 210 b) 211 c) 212 d) 209​
fond the missing number in the series? ​

Answer 1

Answer:

2³-1 = 7

3³-2 = 25

4³-3 = 61

5³-4 = 121

6³-5 = 211 (Ans)

(Mark as brainlist)

Answer 2

Answer:

Option (b)211 is the missing number in the series.

Step-by-step explanation:

Explanation:

Given in the question, 7,25,61,121,

So, from the question, we need to find out the next number in the series.

Now, 7 can be written as,

7 = $2^3$ - 1           [Where value of $2^3$ is 8]

Similarly, 25 can be written as,

25 =$3^3$ - 2              [where value of $3^3$ is 27]

So, to find the next  number  in the series we need to apply this formula $[n^3 - (n-1)]$

⇒ 61 = $[4^3 - (4-1)]$ = $4^3 -3$                    [where value of $4^3$ is 64]

⇒121 = $[5^3 - (5-1)]$ = $5^3 -4$                    [where value of $5^3$ is 125]

Similarly, we take n = 6.

⇒$[6^3 - (6-1)]$ =  6×6×6 - 5 = $216$ - 5 = 211.

Final answer:

Hence, 211 is the missing number in the series.

#SPJ3