Question

There are 90 multiple-choice questions in a test suppose you get two marks for every correct answer and for every question you leave and attempted or answer only one mark is deducted from your total score of correct answers if you get 60 marks in the test then how many questions did you answer correctly

Answer 1

Answer:

50

Step-by-step explanation:

We have to find the number of correct questions answered by Sahana.

We have, total number of questions =90

Let us assume x to be the number of questions answered correctly. Then, we can find the number of incorrectly answered questions by subtracting x from 90.

Number of incorrectly answered questions 

=90−x=90−x

It is given that 2 marks are awarded for every correct answers. Hence, we can get the number of marks scored for correct answers as shown below.

Number of marks scored for correct answers =2x

We know that 1 mark is deducted for every wrong answer. Hence, the number of marks to be deducted for wrong answers is given by

Number of marks to be deducted for wrong answers =(90−x)×1=(90−x)=(90−x)×1=(90−x)

We know that Sahana scored 60 marks. Hence, we can write the total marks scored by Sahana as

Number of marks for correct answers−number of marks for wrong answers=Marks scored by SahanaNumber of marks for correct answers−number of marks for wrong answers=Marks scored by Sahana

Let us now substitute the values. We will get

2x−(90−x)=60⇒2x−90+x=602x−(90−x)=60⇒2x−90+x=60

Let us collect the constants to one side and variables in the other.

2x+x=60+902x+x=60+90

Let us solve this.

3x=150⇒x=1503⇒x=503x=150⇒x=1503⇒x=50

Hence, the number of correct questions answered by Sahana is 50.