Whenever Martin has a restaurant bill with an amount b/w $10 & $99, he calculates the amount of the tip as 2 times the tens digit of the amount of his bill. If the amount of Martin's bill was b/w $10 and $99, was the tip calculated by martin on his bill greater than 15% of the amount of the bill?

1. The amount of the bill was between $15 and $50

The tip calculated by Martin was $18