Question

$A=\left\{\right(a,b):b=2a-5\}$ If $(m,5)and(6,n)$ are the member of set A then m and n are respectively

• A. $5,7$
• B. $7,5$
• C. $2,3$
• D. $5,3$

Answer 1

The correct option is A

$5,7$

Explanation for the correct options:

Step $1$ : Finding the value of m

Given, $A=\left\{\right(a,b):b=2a-5\}$, then equation is $b=2a-5......\left(i\right)$

Now, using $(m,5)$ in equation $\left(i\right)$ where, $a=m\&b=5$

$\begin{array}{rcl}5& =& 2\left(m\right)–5\\ m& =& 5\end{array}$

Step $2$ : Finding the value of n

Using $(6,n)$ in equation $\left(i\right)$ where,$a=6\&b=n$

$\begin{array}{rcl}n& =& 2\left(6\right)–5\\ n& =& 7\end{array}$

Therefore,

$m=5\&n=7$

Hence, Option(A) is correct.