Question

The figure shows a rectangle with a perimeter of $60cm$.
What is the value of $k$?

• A. $7$
• B. $9$
• C. $12$
• D. $29$

Answer 1

The correct option is A $7$

Given length of rectangle is $(3k-2)$ cm and breadth is $(k+4)$ cm

Then, perimeter $=2\left[\right(k+4)+(3k-2\left)\right]$

But perimeter given IS $60$ cm

$\therefore 2\left[\right(k+4)+(3k-2\left)\right]=60$

$\Rightarrow (k+4+3k-2)=30$

$\Rightarrow k+3k=30-4+2$

$\Rightarrow 4k=28$

$\Rightarrow k=7$