9^2*4^4 is the correct answer I believe.
The equation would be 40+15p=70+5p. You would subtract 5p from each side (15-5) and (5-5) and you'll have 40+10p=70. You would then subtract 40 from each side (70-40) and (40-40) to have 10p=30. You would divide by both of the sides by 10, you would end up with p=3. P is price training. The reason you divide and subtract on both sides is because you want the months to be on one side and the price training on the other side.
This is a binomial probability situation, since a dog either is adopted or is not adopted. The chances of a dog's being adopted in 0.20. Here we're speaking of 9 visits. Thus, n=9, p=0.20.
One way of doing this problem is to calculate the probability that ONE dog will be adopted, and then that that TWO dogs will be adopted, and so on, up to NINE dogs. Add together these nine probabilities to get your answer.
But a better (faster) approach would be to calculate the probability that ZERO dogs will be adopted, and then to subtract this from 1.000.
Using my TI-84Plus calculator, I figured that P(0 dogs will be adopted) is binompdf(9,0.20,0), or 0.134. Subtracting this from 1.000, we get 0.866 (answer to this problem).
If 1.5 and 2.5 are the height and base, then just use Pythagorean theorem,
500 (the current collection) + 10 (the weekly addition) x 20 (weeks to add)
500 + 10*20 (Multiplication comes before addition)
500+200
700
another way I can phrase it
500 total right now
each week he adds 10
after 20 weeks he will have x books
20 weeks=10 times 20 books added=200 books added
500+200=700
answer is 700
