The LCM of 15 and 63 is 315 63x5=315 15x21=315.
5/12 of 378 is found by multiplication. You multiply 378 by 5 then divide by 12. So the first step gives us 1890 and then when we divide we have 315/2 which is 13.125. It sometimes helps to not multiply such big numbers. You might note that 378 divided by 12 is 63/2, then we just need to multiply 63x5 which is 315.
It depends on the proof (strength) of the vodka.For a 1.5 ounce shot here are the calories:70 proof: 85 calories80 proof: 100 calories90 proof: 115 calories100 proof: 130 calories