Um, what operations? You didn't list any...
Multiply secondsn by 60 add to minutes multiply by 60 and to degrees
5/6 is not the definite ratio, when you take a larger sample size it could be off by a bit like 499/600 or 501/600
No to not being able to get both.
25% of 500 is 125. 500 - 125 is 375. Her budget it 390. 390 minus 375 is 15. $15 is not enough to buy $60. She could either buy one or the other.
