Answer:
Step-by-step explanation:
(7 rows)(9 people per row) = 63 people total
Answer:320
Step-by-step explanation:
Answer:
A
Step-by-step explanation:
Just plug in
.
Answer:

Step-by-step explanation:
Given information:
- Total number of pupils = 20
- 3 pupils play the flute
- 6 pupils play the piano only
- 6 play both instruments
We can assume that 3 pupils play the flute <u>only</u> as we have also been told that 6 pupils play both instruments.
To calculate the probability that a randomly chosen pupil plays neither instrument, first determine how many pupils do not play an instrument by subtracting the number of pupils who do play an instrument from the total number of pupils:
⇒ total number of pupils - pupils who play instruments
⇒ 20 - (3 + 6 + 6)
⇒ 20 - 15
⇒ 5
Therefore, 5 pupils do not play the piano and/or flute.
To calculate probability:

Therefore:

X = D/(1 - h)
1 - h = D/x
h = 1 - D/x
D = 400, X = 4000
h = 1 - 400/4000
h = 1 - 0.1 = 0.9