Question

The formula sa

Answer 1

Answer:

The correct option is (b).

Step-by-step explanation:

The formula for the side of a cube of surface area SA is as follows :

$s=\sqrt{\dfrac{SA}{6}}$

When SA = 180 m²

$s=\sqrt{\dfrac{180}{6}}\\\\s=\sqrt{30}$

When SA = 120 m²

$s=\sqrt{\dfrac{120}{6}}\\\\s=\sqrt{20}\\\\=2\sqrt5$

Difference,

$=30-2\sqrt5$

So, the correct option is (b).