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maths

in a cylinder, there are 3 balls. the height of the cylinder is 12cm, the diameter of the top of the cylinder is 4cm and the diameter of each ball is 4cm.
work out the volume of the remaining space where there are no spheres in the cylinder. (the non gray parts in the picture attached)
the volume of a sphere is 4/3 pi r 3
sorry, this may not make sense well because I got this question in a maths paper yesterday so i do not remember the actual wording of it and I am really sorry i cannot use the symbol of pi so i just wrote it out. please, can u help me know the answer and how to work it out?

(edited 5 years ago)

cylinder.png6.9KB

Reply 1

Moe_00

You need to work out the volume of the empty cylinder, then the volume of a ball x3. Then subtract the two to get the empty space.

Reply 2

help_me_learn

Original post by Mshabana

You need to work out the volume of the empty cylinder, then the volume of a ball x3. Then subtract the two to get the empty space.

i did that but a lot of us got different answers so can u work it out and tell me what the answer is?

Reply 3

Moe_00

Some of you probably did similar mistakes, what did you get?

Reply 4

help_me_learn

Original post by Mshabana

Some of you probably did similar mistakes, what did you get?

48/3 pi

Reply 5

shahzaibali___

It should be 48 pi - 32 pi to give 16 pi as the answer or 50.3 cm^3

Reply 6

help_me_learn

Original post by shahzaibali___

It should be 48 pi - 32 pi to give 16 pi as the answer or 50.3 cm^3

can u show me how you worked it out pls?

Reply 7

Moe_00

That's the same as I got, so it should be right unless I also made a mistake.
Note that it simplifies to 16π so maybe that's where the confusion came from

thank you so much!

Original post by jb2510

Reply 10

help_me_learn

ahh i get it now...thank u!

Original post by Mshabana

That's the same as I got, so it should be right unless I also made a mistake.
Note that it simplifies to 16π so maybe that's where the confusion came from