Patna-mart, sister concern of Wal-mart, is planning to establish a mechanism to give discount. It is actually a Khul Ja Simsim kind of game where if you win any round, you will get some discount specific to that round, and it you lose, you will be losing all the discounts so far won.
Now, round 1 is having discount coupons of 2%.
Round 2 is having discount coupons of 4%.
Round 3 is having discount coupons of 6%.
And so on…………
There are infinite rounds and you can participate in all the rounds but you can participate in any round only once and before participating in round N (any particular round), you should have participated in round 1 – round N-1 (all the rounds before that particular round.)
All the discounts won will be successive, e.g., if you win Round 1 and then round 2 also, you will get a successive discount of 2% and then 4%. But again as the rule goes on, if you lose round 3, you will be losing all the discount coupons won so far. But despite losing round 3, you can participate in round 4 and hence.
What is the minimum possible discount after 20 rounds provided that customer has won a minimum of 18 rounds?