Answer:
b. Because the probability of being 15 or more correct is 0.0207, it is likely that she is just guessing at the questions.
Step-by-step explanation:
-This is a binomial probability distribution with p=0.5, n=20 and x=15.
The function is expressed as:

We calculate the probability of guessing 15 or more correctly:

The probability of passing, guessing 15+ correctly, is 0.0207. This probability is very low and it is it is likely that she is just guessing at the questions
Well 5 1/4 hours is 5 hours and 15 minutes and 2/3 of 5 hours and 15 minutes or 315(5*60+15) is 210
hope it helped
Answer:
yes
Step-by-step explanation:
Only the lengths change, not the angles.
Given that Erica and AAron,are using lottery system to decide who will wash dishes every night.
They put some red and blue power chips and draw each one. If same colour, Aaron will wash and if not same colours Erica will wash
If the game is to be fair, then both should have equal chances of opportunity for washing.
i.e. Probability for Erica washing = Prob of Aaron washing
i.e. P(different chips) = P(same colour chips)
Say there are m red colours and n blue colours.
Both are drawing at the same time.
Hence Prob (getting same colour) = (mC2+nC2)/(m+n)C2
Probfor different colour = mC1+nC1/(m+n)C2
The two would be equal is mC2 +nC2 = m+n
This is possible if mC2 =m and nC2 = n.
Or m = 2+1 =3 and n =3
That for a fair game we must have both colours to be 3.