Answer:
12 male teachers
Step-by-step explanation:
If the ratio is 3:4, and the number of female teachers is 16, then the number of male teachers must be 12. This can be confirmed by multiplying both 3 and 4 by 4, or 12/16 = 3/4.
Answer: B.
Step-by-step explanation: The probability that a student is 15 years old includes those who are only 15: 450 students. This means that of 1,500 there are 450 students who are 15. The probability is set up as: 450/1,500 or 0.30.
Answer:
40.8 minutes
Step-by-step explanation:
Element X decays radioactively with a half life of 8 minutes. If there are 480 grams of Element X, how long, to the nearest tenth of a minute, would it take the element to decay to 14 grams?
The formula to find how long it would take which is the time elapsed is given as:
t = t½ × In(Nt/No)/-In2
t = ?
t½ = 8 minutes
Nt = Amount after the time of decay = 14 grams
No = Original Amount of substances = 480 grams
t = 8 × In(14/480)/-In2
t = 40.796285388407 minutes
Approximately to the nearest tenth = 40.8 minutes
Therefore, it would take the element X, 40.8 minutes to decay to 14 grams
