Answer:
464
Explanation:
The first term is 9.
The difference between the second and first term = 20 - 9 = 11
The difference between the third and second term = 39 - 20 = 19
The difference between the fourth and third term = 72 - 39 = 33
The difference between the fifth and fourth term = 125 - 72 = 53
The difference between the sixth and fifth term = 204 - 125 = 79
The difference between the seventh and sixth term = 315 - 204 = 111
The differences are 11, 19, 33, 53, 79, 111
From the difference: 19 - 11 = 8, 33 - 19 = 14, 53 - 33 = 20, 79 - 53 = 26, 111 - 79 = 32
We can see from the first difference (8), if we add 6 we get 14, if we add another 6 we get 20, if we add 6 we get 26, if add 6 we get 32
We get the eight term using:
32 + 6 = 38
let x be the difference between the eight term and the seventh term, hence:
x - 111 = 38
x = 111 + 38
x = 149
Therefore:
eighth term - seventh term = 149
eighth term - 315 = 149
eighth term = 149 + 315
eighth term = 464
The next probable term is 464