Each cone of the hourglass has a height of 12 millimeters. The total height of the sand within the top portion of the hourglass is 47 millimeters. The radius of both the cylinder and cone is 4 millimeters. Sand drips from the top of the hourglass to the bottom at a rate of 10π cubic millimeters per second. How many seconds will it take until all of the sand has dripped to the bottom of the hourglass? (4 points)

1. it's 4 points.

2. We have to calculate the height of a cylinder : h2 = ( 45 - 2 · 15 )/ 2 = 15 / 2 = 7.5 mm

Volume of the bottom of the hourglass:V = 1/3 r² π h1 + r² π h2 = = 1/3 · 6² · 3.14 · 15 + 6² · 3.14 · 7.5 = = 1/3 · 36 · 3.14 · 15 + 36 · 3.14 · 7.5 = = 565.2 + 847.8 = 1,413 mm³The rate is 10 π mm³/ sec = 31.4 mm³/secTime = 1,413 : 31.4 = 45 sec.

It will take 45 seconds.

3. (5x + 1) - (-10x + 6)

simplify the answer choice. combine like terms. remember to distribute the negative to the terms inside the second parenthesis. also remember that two negatives = one positive, and one of each sign = negative.

- (-10x + 6) = + 10x - 6

simplify. combine like terms:

5x + 1 + 10x - 6

5x + 10x + 1 - 6

15x - 5

∴ it is your answer

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16.80 times .20= 3.36

step-by-step explanation: