2.4k views

A test has twenty questions worth $100$ marks in total. There are two types of questions. Multiple choice questions are worth $3$ marks each and essay questions are worth $11$ marks each. How many multiple choice questions does the exam have?

1. $12$
2. $15$
3. $18$
4. $19$

edited | 2.4k views

Ans: B.15

Let the number of MCQs be $x$ and number of essay questions be $y$.
Given MCQs are worth $3$ marks each and essay questions are worth $11$ marks each.
Also, total number of questions is $20$ worth $100$ marks in total.

$\Rightarrow x+y = 20$ and $3x+11y = 100.$
$\Rightarrow 3x+11(20-x) = 100$
$\Rightarrow 8x = 120$
$\Rightarrow x =\dfrac{120}{8} = 15$

edited

X Multiple choice Question

Y Essay Question

X+Y=20

(X*3)+(Y*11)=100

Hence X=15 and Y=5

Ans B

+1 vote Hope it might help......

A test has twenty questions worth 100 marks in total. There are two types of questions. Multiple choice questions are worth 3 marks each and essay questions are worth 11 marks each. How many multiple choice questions does the exam have?

20 questions

totol 100 marks

Multiple choice questions are worth 3 marks each and essay questions are worth 11 marks each.

x+y=20----------------------------------------------------------1

3x+11y=100---------------------------------------------------2

solve 1 and 2

x=15 so MCQ are 15