Difficulties on opertions with variables

Question

why haven't we got the good result of 49.5 and why. 49.50000000001 ?
https://code.sololearn.com/cDgIcb6DegBY/?ref=app

Answer 1

You can use printf() method for formatting floating numbers.
System.out.printf("%.2f",var2);

Answer 2

floats and double cannot be precise, because of their binary representation. It often leads to this type of errors, due to floating point precision.

Answer 3

It's due to Rounding Error.

Answer 4

1.1 can't be represented as a binary decimal number.

Answer 5

Thank you Theophile, Soheil, Magat Sam and Seb TheS!!!