The formula for volume of a cylinder is V = pi r^2 h. You put the numbers into the formula, and you get 25.13. So the volume of the cylinder is 25.13. The formula for volume of a cone is V = pi r^2 h/3. You put the numbers into the formula, and you get 12.57. The volume of the cone is 12.57. Then, you add the volumes of the two shapes together. 25.13 + 12.57 = 37.7. You have to round it to the nearest whole number, so since 7 is greater than 5, you round up to 38. 38 mm is the answer.