# 8th grade math

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A spherical balloon has a volume of 268 cubic cm. If more air is pumped in so that its radius is 3 times as long, what is its new volume?

My answer: 2,412 cubic cm

• 8th grade math -

r^3 Becomes (3r)^3 = 27r^3,

New Volume = 27 * 268 = 7236 cc.

ALTERNATE METHOD:

V = (4/3)3.14*r^3 = 268 cc,
4.1888r^3 = 268,
r^3 = 268 / 4.1888 = 63.980,
r1 = 4.

New Radius = r2 = 3r1 = 3*4 = 12cm.

New Volume:

V = (4/3)3.14*(12)^3,
V = 4.1867 * 1728 = 7235 CC.

• 8th grade math -

6 negative 3

• 8th grade math -

i need help

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