Two spherical pieces of cookie dough have radii of 3cm & 5cm. The pieces are combined to form one large spherical piece of dough. What is the approximate radius of the new sphere of dough?

Question

radar · Answer

I am thinking we need to find the total volume of these two cookie dough balls using the formula: V=(4/3)pi r cubed$$V=4/3\times pi \times r ^{3}$$

radar · Answer

I will compute the volumes of the 5 cm radius ball.
$$V=4/3 \times pi \times 5^{3}=523.6 cm ^{3}$$
You can compute the volume of the 3 cm cookie dough ball.
Combine the two volumes (add) you will have the total volume.  Then use the volume formula and solve for radius.