Question

400, 274, 209, 181, 172, ? (a) 169 (b) 173 (c) 168 (d) 171 (e) 170

Answer 1

Answer:

400, 274, 209, 181, 172, 170

Step-by-step explanation:

Pattern of series

$\(400-\left(5^{3}+1\right)=274\)\\\(274-\left(4^{3}+1\right)=209\)\(209-\left(3^{3}+1\right)=181\)\\\(181-\left(2^{3}+1\right)=172\)\\\(?=172-\left(1^{3}+1\right)=170\)$

Answer 2

Given:

The series - 400, 274, 209, 181, 172

To Find:

The next number in series

Solution:

The series follows a pattern of subtracting as well as cubing.

Thus, the pattern followed is -

400 - ( 5³ - 1)

= 400 - ( 125 + 1) = 400 - 126 = 274

274  - ( 4³ + 1)

= 274 - ( 64 + 1) = 274 - 65 = 209

209  - ( 3³ + 1)

= 209 - ( 27 + 1) = 209 - 28 = 181

181  - ( 2³ + 1)

= 181 - ( 8 + 1) = 181 - 9 = 172

172   - ( 1³ + 1)

= 172 - ( 1 + 1) = 172 - 2 = 170

Thus, the series will be - 400, 274, 209, 181, 172, 170

Answer: The next term in the series is (e) 170