Tammy scored 88, 72, 44 points on her first three test. What must she score in her last test to get at least an average of 70?
1 answer:
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Answer:
(a) 7 essays and 29 multiple questions
(b) Your friend is incorrect
Step-by-step explanation:
Represent multiple choice with M and essay with E.
So:
--- Number of questions
--- Points
Solving (a): Number of question of each type.
Make E the subject of formula in
Substitute 36 - M for E in
Collect Like Terms
Divide both sides by -4
Substitute 29 for M in
Solving (b): Can the multiple questions worth 4 points each?
It is not possible.
See explanation.
If multiple question worth 4 points each, then
would be:
Where x represents the number of points for essay questions.
Substitute 7 for E and 29 for M.
Subtract 116 from both sides
Make x the subject
Since the essay question can not have worth negative points.
Then, it is impossible to have the multiple questions worth 4 points
<em>Your friend is incorrect.</em>