Please help me with the activity below (WITH SOLUTIONS)

I need a step by step solutions please.

I. Perform the following with solutions 1. /+ 1/3+% - 1/5 2. 12/3-1/5 3. /4(2/3- 72) 4. 2/5+.04 5. 24 % of X II. Convert to desired units (show your solution) 1. 4 ft to mm 2. 45 miles to km 3. 56 m to square inch 4. 42 psi to mmHg 5. 100 C to "F III. Solve the following problems. Show your solution. 1. Find the volume of a sphere with a diameter of 4 ft. 2. What is the mass of an iron cube with a side of 2 cm