Answer:
7..the way you worded the options was confusing
Answer:
1/5
Step-by-step explanation:
(5^7*5^5)/5^13 (when multiplying numbers with the same base, add the exponents)
= (5^12)/5^13 (when dividing exponents with the same base, subtract the exponents)
= 1/5^1 (anything to the first power is itself)
= 1/5
~ ANSWER=1/2 ~
Simple probability is found by counting all the results which fit requirements and dividing by all possible results.
To find probability of two results in a row, multiply chance of first result by chance of second result.
Since you are replacing the marble before the second draw, we don’t have to figure out the various changes in odds for the different possible first draws. It’s just that simple.
There are 5 white marbles
There are 4 red marbles
There are always 20 marbles in all
5/20*4/20=1/4*1/5=1/20 or 1/2
By coincidence, the same as the chance of drawing the white marble in one draw.
There are many ways to solve number 5 as it is just an reduce/enlargement of equidistant fractions
The first method that came up to my mind is just dividing denominators.
For A) you can do 72 divided by 18 which would give you 4. Then you can divide the given numerator with the answer you got from dividing the denominators. This would be 8 divided by 4 which would give you two. This means that 2/18 is equal to 8/72. You can check by simplifying the fraction. Both 2/18 and 8/72 equal 9 when simplified, therefore correct.
You can use this method for b, either use a calculator because of the decimals or just remove the decimals and replace them later. Make sure when you use this method, you are always dividing the bigger number. So in B you would do 40.3 divided by 12.4
N - 7 = 9 if you want it written in equation form