Question

A question bank has 10 questions worth 100 marks. It consists of multiple choice questions worth 10 marks each and yes/no questions worth 3 marks each. How many multiple choice questions are on the question bank?

• A. 15
• B. 12
• C. 10
• D. 13

Answer 1

The correct option is C 10

Let us assume $x=$ Multiple Choice questions
Let $y=$ Yes/No questions
Then as per the given statement form equations,

$\Rightarrow$$x+y=10$ ----- (1)
$\Rightarrow$$10x+3y=100$ ----- (2)

Multiply the equation (1) by 3 and then subtract the equations (3) and (4), we get

$3x+3y=30$ ----- (3)
$10x+3y=100$ ----- (4)
_____________
$-7x=-70$

$x=\frac{-70}{-7}=10$
Therefore, there are 10 multiple choice questions.