If the diameter of a circle changes from 5 cm to 15 cm, how will the circumference change? a) multiplies by 1 3 b) multiplies by 3 c) increases by 10 d) decreases by 10

Given that diameter of the old circle = 5 cm

Given that diameter of the new circle = 15 cm

Now we have to find the change in circumference from old to new circle.

To find that we need formula of circumference of the circle which is

circumference = D \pi

where D represents diameter of the circle.

Then ratio of the circumference of the both circle is given by

That means circumference of the new circle is 3 times more than old circle.

Hence choice "B) multiplies by 3" is correct.

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step-by-step explanation:

for exempl this   system of equations   y = x - 3

                                                                y = 2x - 5

look   the line : y = x -3     ( red)

                            the line : y = 2x -5 ( bleus)