a solid pyramid with a square base with side 12 cm and height 25 cm is made of metal. The metal is melted to form spherical ball bearings of radius 7 mm. How many pyramids are needed to form 2490 ball bearings?

3 pyramids.

Step-by-step explanation:

The volume of one pyramid is 1/3 * b^2 * h

= 1/3 * 12^2 * 25

= 1200 cm^3.

The volume of one ball bearing = 4/3 * π * 0.7^3

= 1.43676 cm^3.

Therefore the volume of 2490 ball bearings = 2490 * 1 .43676

= 3577.53 cm^3.

So we need 3577.53 / 1200 = 2.98 = 3 pyramids.

blue marble is 15 times out of 50 = 15/50 reduces to 3/10

landing on tails is 24 out of 50 = 24/50 reduces to 12/25

to find the probability of both multiply together:

3/10 x 12/25 = 3 x 12 / 10 x 25 = 36/250

if you multiplied the numerator and denominator by 10 you get 360/2500.

the answer is 360/2500

stops on an even number.