SSC JE Mechanical Engineering 27 Sep 2019 Shift 2 Paper

The given sequence can be written as:
5 × 2 - 3 = 7
18 × 3 - 3 = 51
69 × 5 - 5 = 342
2, 3 are the prime numbers. So we can say that next number N will be
N = 69 × 5 - 3 = 342
Note: Next number is multiple of last number and prime number minus 3.
So the answer is N = 342.