Help me please ASAP (solve by elimination)

Estimate the area under the curve f(x) = 16 - x^2 from x = 0 to x = 3 by using three inscribed (under the curve) rectangles. answer to the nearest integer.

Of 400 people at the school carnival, 95% are students and the rest are teachers. a. how many students are at the school carnival? b. if 55% of the students at the school carnival are boys, how many are girls? c. how many teachers are at the school carnival? d. if 35% of the teachers are male and the rest are female, how many female teachers are at the carnival?

Out of 8 boys and 6 girls in a high school, a team of seven students is selected. what is the probability that three boys and four girls are selected? in your response, include an explanation and all of the calculations necessary to determine the probability.