Answer:
Step-by-step explanation:
Let A = Adam, B = Betty
Adam and Betty purchased a printer together for $258.
This means we can say A + B = 258.
We are also told Adam paid $18 less than twice Betty.
You can write this as:
Adam = 2 x Betty - 18
A = 2B - 18
Substitute "A" into the A + B equation and you get:
A + B = 258
2B - 18 + B = 258
3B - 18 = 258
Add 18 to both sides.
3B = 258 + 18
3B = 276
Divide both sides by 3 to find B
B = 276/3 = 92 (This means Betty paid $92).
Since the total that they paid together was $258.
This means Adam pays the Total - How much Betty paid
Adam = 258 - 92 = $166
Answer: The answer is 30%.
Step-by-step explanation: Given that there is a group of 10 light users and 10 heavy users. We are to find the probability that exactly 3 of the 20 users are HIV positive.
We have the following four possible cases -
(i) All 3 are light users.
(ii) 1 is a light user and 2 are heavy users.
(iii) 2 are light users and 1 is a heavy user.
(iv) All 3 are heavy user.
Since there is a 45% chance of a light user to be HIV positive and 55% chance of a heavy user to be HIV positive, so the required probability is given by

Thus, the probability is 30.