SSC CGL 2016 Tier 1 2 Sept Question 15

Question 15.If 12x16 = 188 and 14x18 = 248, then find the value of 16x20 = ?
Options:
1) 320
2) 360
3) 316
4) 318
Answer: 3
12x16 = 188 =>12x16 = 192 - 4
14x18 = 248,=> 14x18 =252 - 4
16 x 20 = 320 - 4 = 316