Math Kangaroo 2021 Problem 17 | Kadett

Try this beautiful Problem based on simple Arithmetic appeared in Math Kangaroo (Kadett) 2021 Problem 17.

Math Kangaroo 2021 Problem 17 | Kadett

There are 20 questions in a quiz. Each correct answer scores 7 points, each wrong answer scores $-4$ points, and each question left blank scores 0 points. Eric took the quiz and scored 100 points. How many questions did he leave blank?

Key Concepts

Arithmetic

Divisibility

Logic Question

Suggested Book | Source | Answer

Algebra by Gelfand

Math Kangaroo (Kadett), 2021

$1$

Try with Hints

Here given that,

Total number of questions $=20$
Score of correct answer $=7$ points
Score of wrong answer $=-4$
Eric scored $=100$ points

So that mean, the score for all of the correct answers is greater than $100$.

Now we know $7\times 16 = 112$.

Now we have to count how many wrong answers are there if the score is $100$.

Remaining question $=20-(16+3)$
So, $1$ is the correct answer.