Step-by-step explanation:
Multiplication of fractions is easiest operation. Simply multiple numerator to numerator and denominator to denominator. For example,
Addition and subtraction requires that we find a common demoninator.
For example,
The common denominator is 12. So I need to muliply each fraction to get the right denominator. 4*3 = 12.
Then we add the numerators
Then we should reduce.
Division is a little trickier because we have to flip-flop the second term and then multiply. For example: 
Answer:5x7=35
8x5=40
Step-by-step explanation: well first think of what number can divide into 40 and 35 and come out as 5. So for example 35 divided 7 equals 5 and 40 divided 8 = 5 so the missing number is either 8 or 7
Answer:
10
Step-by-step explanation:
5/6 =0.8333
12x0.8333 = 10
2/5
Since 12 out of 30 marbles were black, you can assume that the percentage of black marbles in the bag is 40% (Ex: 12/30=.4) The probability that the marble you pick is black is equal to the percentage of black marbles in the bag. 40% is equal to 2/5.
