Respuesta :
Answer:
The number of multiple-choice questions are 15.
Step-by-step explanation:
Mrs. Snell's math test has twenty questions and is worth 100 points.
The test consists of multiple-choice questions and short answer questions.
Let M represents the Multiple choice questions.
Let S represents the short answer question.
It is given that the total number of question are 20.
[tex]S+M=20[/tex] ...(1)
Also, multiple-choice questions worth 3 points each, and short answer questions worth 11 points each. The total worth of the test is 100 points.
[tex]11S+3M=100[/tex] ...(2)
Multiply equation (1) by 3 and subtract from equation (2).
[tex]11S+3M=100\\3S+3M=60\\\underline{-\:\:\: -\:\:\:\:\:\:\:\:-\:\:\:\:\:\:}\\8S\:\:\:\:\:\:\:\:\:\:\:\:\:=40\\S\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:=5[/tex]
The total number of short answers is 5.
Put S=5 in equation 1.
[tex]5+M=20\\M=15[/tex]
Hence, the number of multiple-choice questions are 15.
