Question

Sum of two numbers is 21 and their difference is 11, then the greatest number is

• A. 5
• B. 10
• C. 9
• D. 16

Hint:

When solving for two numbers given their sum and difference, add the two equations to find one variable, then substitute to find the other.

Answer 1

The Correct Option is B

Let the two numbers be \(x\) and \(y\), such that \(x > y\). We are given: \[ x + y = 21 \quad \text{and} \quad x - y = 11 \] By solving this system of equations, we add them: \[ 2x = 32 \quad \Rightarrow \quad x = 16 \] Thus, the greatest number is \(16\).