Question

5, 9, 21, 37, 81 -? remove ?

Answer 1

Series is 5  9  21  37  81  ?

Solution-  5*2-1 = 10-1 = 9
                9*2+3 = 18+3 = 21
                21*2-5 = 42-5 = 37
                37*2+7 = 74+7 = 81
                81*2-9 = 162-9 = 153

So the answer is 153

Answer 2

Answer:

Therefore, The sequence is 5, 9, 21, 37, 81, 153

Step-by-step explanation:

9 is obtained by :

5 × 2 - 1 = 10 - 1 = 9

21 is obtained by :

9 × 2 + 3 = 18 + 3 = 21

37 is obtained by :

21 × 2 - 5 = 42 - 5 = 37

81 is obtained by :

37 × 2 + 7 = 74 + 7 = 81

Similarly, The next number will be obtained by multiplying the previous number by 2 and doing the alternate addition and subtraction of the odd numbers in the increasing order

⇒ Next number = 81 × 2 - 9 = 162 - 9 = 153

Therefore, The sequence is 5, 9, 21, 37, 81, 153