I need help with these work sheet questions! Final answer included !

8. A trough is 12 m long and its ends are in the form of inverted isosceles triangles with height 3 m and base 3 m. If water is flowing into the trough at the rate of 2 m /min, how fast is the water level rising when the water is I m deep? [1/6 m/min] 9. A man on a dock is pulling in a small boat at the rate of 50 fumin by means of a rope attached to the boat. If the man's hands are 16 ft above the point where the rope is attached to the boat, determine how fast the boat is approaching the dock when it is 10 ft from the dock. [94.3 fu/min 10. If the length of the side of an equilateral triangle is increasing at the rate of 3 cm/min, how fast is the area of the triangle increasing when the length of the side is 8 cm? [12v3 cm /min] 11. A funnel in the shape of a right circular cone is 10 cm across the top and has a height of 8 cm. Water is flowing into this funnel at the rate of 12 cm'/s and out at a rate of 4 cm /s. How fast is the water level rising when the depth of the water is 5 cm? [512/625m cm/s]