A rock is dropped into a graduated cylinder containing 40mL of water. the new volume is 47mL. What is the volume of the rock? a) 4ml b) 47ml c) 7ml d) 87ml e) 11ml

I thibk it is 7ml am I correct?

To find the volume of irregularly shaped objects, you put them in graduated cylinders, as described. To find the volume of the object, get the difference between the original volume and the new volume.

So, its 47mL - 40mL, which equals 7, so choice c) 7mL, the answer you picked!