Answer: 3
Step-by-step explanation:
Let E be the event of that student pierces ear and N be the event of that student pierces nose.
Given: 

For any two event A and B, we have

Similarly , 

Hence, 3 students have piercings both on their ears and their noses.
Answer:
20 minutes
Step-by-step explanation:
The mean, or average of a data set can be found by adding all the values together, and dividing by the number of values.
The data set is: 20 minutes, 22 minutes and 18 minutes
1. Add the values together
Add all the numbers in the set together.
Data set: 20, 22, 18
Add them: 20+22+18
60
2. Divide by the number of values
Count how many numbers are in the set.
In this set, there are 3 numbers.
Divide 60 by 3
60/3 =20
20 minutes
His mean time is 20 minutes.
Okay what is the question?
A) draw a cube
i) 16cm
ii) 80 cm
b)64 cm
Ok so draw the outline of a cube with 4cm each. There is six sides and the area is just multiplying 4 by 4. So, since the area of each side is 16, and there is 6 sides, the surface area is 80 cm. The volume is just length x width x height (4x4x4) so it’s 64 cm cubed.
Answer:
160+4h=70+7k
Step-by-step explanation:
h(160))
k(70)
4h=7k