Question

3,15,35, ..........,99,143​

Answer 1

Add 1 to each term of the series, then the series changes to:

4(2^2), 16(4^2), 36, 64, the next number in this series should be 10^2

So, the term in our series must be 10^2 - 1 =99

There is also another way to solve this series take the differences

3, 15, 35, 63

First level difference: 12, 20, 28

Second level difference: 8,8

So, the next 2nd level difference must also be 8

Hence, the next 1st level difference must be 28 + 8 = 36

Giving us the next term as 63+36=99

You can continue as much as you want :)