sentence 1: How do I know if I'm good?
 sentence 2: How do I know what I'm good at? sentence 1: What is the most effective way of getting rid of pimples?
 sentence 2: How effective is toothpaste in getting rid of pimples? sentence 1: How does CouponDunia actually work?
 sentence 2: How coupondunia get revenue?
not same meaning
not same meaning
same meaning