Answer:
22
Step-by-step explanation:
mean is calculated as
mean =
Given the mean of 12 numbers is 20 , then
= 20 ( multiply both sides by 12 )
sum = 240
Given the mean of 8 numbers is 25 , then
= 25 ( multiply both sides by 8 )
sum = 200
Total sum of the 20 numbers = 240 + 200 = 440, then mean of 20 numbers is
mean = = 22
Conditional statement is a statement with a hypotesis and a conclusion:
or mathematically .
Converse statement of is statement
.
If you negate (that means stick a "not" in front of) both the hypothesis and conclusion, you get the inverse:
.
Finally, if you negate everything and flip p and q (taking the inverse of the converse) then you get the contrapositive:
.
Example:
1. Conditional statement: If I am sleeping, then I have closed eyes. (true)
2. Converse statement: If I have closed eyes, then I'm sleeping. (not necessarily true)
3. Inverse statement: If I'm not sleeping, then I haven't closed eyes. (not necessarily true)
4. Contrapositive statement: If I haven't closed eyes, then I'm not sleeping. (true)
Step-by-step explanation:
We get two equations here. One for the area and one for the perimeter. The area gives us x×y=50. The perimeter, if we have a rectangle, x+y+x+y=30=2x+2y. For this to work we need to make a simple expression for x or y. Let's go with x here. 2x+2y=30 so x=15-y. if we fill that in the other equation we get (15-y)×y=50 (see picture). y=5 or y=10. If we fill in x×5=50 we get x=10 and vice versa. So the dimensions are 5 centimeters by 10 centimeters
