199, it rounds to 200 because it's closer to 200 than 100. It is also closer to 200 than to 190. And finally, 1 + 9 + 9 = 19
V(t) = dy/dt = 40 - 32t
ai). average velocity = (v(0.5) - v(0))/(0.5 - 0) = ((40 - 32(0.5)) - (40 - 32(0)))/0.5 = (40 - 16 - 40)/0.5 = -16/0.5 = -32m / s
ii). average velocity = (v(0.1) - v(0))/(0.1 - 0) = ((40 - 32(0.1)) - (40 - 32(0)))/0.1 = (40 - 3.2 - 40)/0.1 = -3.2/0.1 = -32m / s
iii). average velocity = (v(0.05) - v(0))/(0.05 - 0) = ((40 - 32(0.05)) - (40 - 32(0)))/0.05 = (40 - 1.6 - 40)/0.05 = -1.6/0.05 = -32m / s
If there are 20 groups of 10, then there are 200 pencils. Subtract 200 and 137 to get the number of dull pencils.