Question

In our own planet Earth, 361,419,000 square kilometre of area is covered with water and 148,647,000 square kilometre of area is covered by land. Find the approximate ratio of area covered with water to area covered by land by converting these numbers into scientific notation.

Answer 1

Given,  Area covered by water = 361419000 km²

Area covered by land = 148647000 km²

Convertion of area into scientific notation,

361419000 = 361419 × 10³

Also, 361419 = 3.61419 × 10⁵

So, 3.61419 × 10⁵ × 10³ = 3.61419 × 10⁸

∴ Area covered by water = 3.61419 × 10⁸ km²

Similarly, 148647000 = 148647 × 10³

Also, 148647 = 1.48647 × 10⁵

So, 1.48647 × 10⁵ × 10³ = 1.48647 × 10⁸

∴ Area covered by land = 1.48647 × 10⁸ km²

Let 3.61419 × 10⁸ ≈ 3.6 × 10⁸

and 1.48647 × 10⁸ ≈ 1.5 × 10⁸

∴ Ratio of water to land = `3.6/1.5` = 12:5