1.The sand pouring at the bottom of an hourglass is conical in shape such that the radius is always 1/3 of the height. When the height is 2 inches, the height is increasing at 0.49 in/s. Find the rate at which the radius of the base is changing in in/s. Express your answer in 3 decimal places.

2.The exact simple interest of P5200 invested from June 21, 1992 to December 25, 1995 is P1,779. What is the rate of interest in %? Express your answer in 2 decimal places.

3.Find the ordinate of the centroid of the region bounded by the parabola y = x²and the line y = 2x + 2 in the second quadrant. Express your answer in 4 decimal places

4.Find the volume of the solid obtained by revolving about the x-axis the region bounded below by the parabola y = 2-x²and above by the parabola y = x². Express your answer in 1 decimal place.

5. Find the area of the surface of revolution generated by revolving about the x axis the arc of the parabola x²= 12y from x = 0 to x = 4. Express your answer in 2 decimal places