Question

I have a roof that measures 175 ft by 45 ft. During the hurricane 11 inches of rain fell.

1 mL = 1 cm?. 20 drops = 1 mL. How many raindrops fell on my roof?

Answer 1

4.1 billion

Explanation:

1 ft = 30.48 cm

1 in = 2.54 cm

The volume of rain that fell on the roof is given by ...

V = LWH

V = (175 ft × 30.48 cm/ft)(45 ft × 30.48 cm/ft)(11 in × 2.54 cm/in)

= 175×45×11×30.48²×2.54 cm³ = 204,412,236.336 cm³

At 20 drops per cm³, this will be ...

20×204,412,236.336 ≈ 4,088,244,727 . . . . raindrops

About 4.1 billion raindrops fell on your roof.