4th girl name is AMBW Logic is all name start with a so first letter is A
Second letter preceeded by 3 so it is M
Third for all is B so it is B
And last is one step backward move from D previous one so it AMBW
1. Assume each coin is with 1 gram weight except that counterfeit coin
step-1: 80 in first step divide into 2 halves i.e 40+40
step-2: take the 40 which is not getting exact 40 weight and then divi...