CAT Number Theory — practice questions

Explore 1 free Number Theory questions in CAT Quantitative Reasoning. Open each question or exercise to read its content, reference answers and available explanation.

Practise Number Theory with Quill →

Number Theory questions and exercises with answers

Showing questions 1–1 of 1.

If 3x + 7y is a multiple of 11, then which of the following is divisible by 11?Read the answer and worked solution →

Worked practice questions

If 3x + 7y is a multiple of 11, then which of the following is divisible by 11?

4x + 6y
4x − 9y
9x + 4y
x + y + 4

Show answer and solution

Correct answer: B. 4x − 9y

1. Given 3x + 7y ≡ 0 (mod 11). 2. Multiply both sides by 4: 12x + 28y ≡ 0 → x + 6y ≡ 0 → 4x + 24y ≡ 0 → 4x + 2y ≡ 0 (mod 11). Also 4x − 9y has 4x ≡ -2y so 4x − 9y ≡ -2y − 9y = -11y ≡ 0. 3. Therefore 4x − 9y is divisible by 11. _Source: KMAT Karnataka 2021 PYQ Q.34_

Open this question →

How to practise

Choose a Number Theory question and try to work out your answer.
Open the question to check the correct answer and read its worked solution.
Continue in the app for bite-sized lessons, explanations and review with Quill. You can start without creating an account.

Put it into practice

Continue with Number Theory practice for CAT. Read explanations as you go. No signup form needed to start.

Practise Number Theory →