In order to easily answer the question, find out what 1/5 of 65 is. To do this, divide 65/5. This is 13. Once you have 1/5 of 65, then simply multiply this number by 3 to get 3/5. 13 * 3 is 39. 39 is 3/5 of 65.
Alternatively, you could multiply 65 by 0.6 which also yields 39. To do this, multiply 65 by 6, which gets you 390, then move the decimal point over to the left one spot becuase you were multiplying by a .6.
