Answer:
13.4%
Step-by-step explanation:
Use binomial probability:
P = nCr p^r q^(n-r)
where n is the number of trials,
r is the number of successes,
p is the probability of success,
and q is the probability of failure (1-p).
Here, n = 16, r = 2, p = 0.25, and q = 0.75.
P = ₁₆C₂ (0.25)² (0.75)¹⁶⁻²
P = 120 (0.25)² (0.75)¹⁴
P = 0.134
There is a 13.4% probability that exactly 2 students will withdraw.
Answer:
9.6
Step-by-step explanation:
This is a four side figure which is most likely to be a trapezium.So AD is the hypotenuse,AB is side (a),BC is the height and CD is side (b).
Answer:
The third side is around 58.043
Step-by-step explanation:
Use the law of cosines: 
Plug in the two sides we know (into a and b) and the angle we know (into angle C).
Thus:
Use a calculator:
(Note: Make sure you're in Degrees mode.)
Answer:
1/4
Step-by-step explanation:
7/12 X 3/7 = 21/84 = 1/4
Answer:
Step-by-step explanation:
To solve this, we are going to make an age table:
Age Now Age 10 years ago
Tanya
Elliot
Filling the in the Age Now column comes from the first sentence. If Elliot is 2 times Tanya's age and we don't know Tanya's age, then Tanya's age is x and Elliot's age is 2x:
Age Now Age 10 years ago
Tanya x
Elliot 2x
Filling in the Age 10 years ago column simply requires that we take their ages in the Age Now column and subtract 10 from each age:
Age Now Age 10 years ago
Tanya x x - 10
Elliot 2x 2x - 10
Since the question is How old is Elliot now based on the fact that 10 years ago....blah, blah, blah, we are using the ages in the 10 years ago column to write our equation. It says:
10 years ago, Elliot was 4 times as old as Tanya. Translated into mathspeak:
2x - 10 = 4(x - 10) and
2x - 10 = 4x - 40 and
-2x = -30 so
x = 15. That means that Elliot is 30 and Tanya is 15
