If 120 is three tenths of a number, the number is

Three tenths written as a fraction is 3/10. You can also write it as a decimal by simply dividing 3 by 10 which is 0.30. If you multiply 0.30 with 120 you will see that you will end up with the same answer as above. You may also find it useful to know that if you multiply 0.30 with 100 you get 30.00.