In a 90-question, multiple-choice test, a student gets
+4 for a correct answer
0 for a question not attempted
-1 for an incorrect attempt.
The total score is the sum of all the marks to the 90 questions. How many total scores are possible?
Any multiple of 4 can be achieved, through 360.
(91 of these, including zero)
One less than a multiple of 4 can be achived through 355.
(89 of these)
Two less than a multiple of 4 through 350.
(88 of these)
Three less than a multiple of 4 through 345.
(87 of these)
That's 355.
But -90 through -1 are also all possible:
355 + 90 = 445.
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Posted by Charlie
on 2019-05-15 16:56:55 |
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