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Bismuth83
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Chair P, from Design Solutions, cost $60 per chair. Chair Q, from Seat 17 Dec 2024, 11:00
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p: 56 q: 28
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

35% (medium)

Question Stats:

77% (01:39) correct 23% (02:10) wrong based on 283 sessions

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Chair P, from Design Solutions, cost $60 per chair. Chair Q, from Seat Unlimited, costs $90 per chair. An office manager often has to buy several chairs to stock the floor space of new offices. On one occasion, she orders p of chair P, and q of chair Q. The average cost of a chair would be

average = \(\frac{60p + 90q}{p + q}\)

In the table, select a value for p and a value for q corresponding to an average cost per chair of $70. Make only two selections, one in each column.
p q Number of chairs
21
28
36
45
56
63
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charlie1195
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Chair P, from Design Solutions, cost $60 per chair. Chair Q, from Seat 17 Dec 2024, 14:37
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This is a weighted average question.

We know that (60p + 90q)/(p+q) = 70
Solving it further, we get
60p + 90q = 70p + 70q
20q = 10p
2q = p

Now, as per the options, there's just one pair of p and q that satisfies this condition, i.e., q=28 and p=56.
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Chair P, from Design Solutions, cost $60 per chair. Chair Q, from Seat 18 Dec 2024, 12:00
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1. The formula and the value for the average can be put together:

\(70 = \frac{60p + 90q}{p + q}\)

2. Since there is no other information given, we can simplify the expression.

\(70 = \frac{60p + 90q}{p + q} \rightarrow 70p + 70q = 60p + 90q \rightarrow 10p = 20q \rightarrow p = 2q\)

3. The only two answers that match a ratio of 1:2 are 28 and 56.

4. So, our answer will be: p - 28 and q - 56.
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