A math teacher graded 45 problems in 3
5
of an hour. At that rate, how many problems can she grade in 1 hour?

75 problems
3/5 of an hours is 36 minutes you can then do 45 over 36 mins and set it equal to x over 60 mins then you do 45 times 60 which equals 2700 then you divide 2700 by 36 and you get 75

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.