-2 + -2 is the same as -2-2=-4
So is a negative number
Answer:
c because its c its c and nothing but c
Let's make the variable P and M.
4M=P
P+6+6+M=57
Let's put the first equation in as Paula's age.
4M+12+M=57
5M+12=57
5M=45
45÷5
9
Mary's present age is 9, so Paula's age is 36.
Let's check the sum of their ages in 6 years.
15+42
57
We have the formula to compute the probability of having exactly k successed over n trials, given a probability p of success (and implicitly a probability 1-p of failure), which is
![P(\text{k successed on n trials}) = \binom{n}{k}p^k(1-p)^{n-k}](https://tex.z-dn.net/?f=%20P%28%5Ctext%7Bk%20successed%20on%20n%20trials%7D%29%20%3D%20%5Cbinom%7Bn%7D%7Bk%7Dp%5Ek%281-p%29%5E%7Bn-k%7D%20)
Now, the probability of at least 3 successes is the union of the following event: exactly three successes,exactly four successes and exactly five successes.
We can compute their probability and sum them:![\binom{5}{3}\left(\frac{3}{7}\right)^3\left(\frac{4}{7}\right)^2 + \binom{5}{4}\left(\frac{3}{7}\right)^4\left(\frac{4}{7}\right)^1 + \binom{5}{5}\left(\frac{3}{7}\right)^5 \approx 0.36788](https://tex.z-dn.net/?f=%20%5Cbinom%7B5%7D%7B3%7D%5Cleft%28%5Cfrac%7B3%7D%7B7%7D%5Cright%29%5E3%5Cleft%28%5Cfrac%7B4%7D%7B7%7D%5Cright%29%5E2%20%2B%20%5Cbinom%7B5%7D%7B4%7D%5Cleft%28%5Cfrac%7B3%7D%7B7%7D%5Cright%29%5E4%5Cleft%28%5Cfrac%7B4%7D%7B7%7D%5Cright%29%5E1%20%2B%20%5Cbinom%7B5%7D%7B5%7D%5Cleft%28%5Cfrac%7B3%7D%7B7%7D%5Cright%29%5E5%20%5Capprox%200.36788%20)
So, the answer is about 36.79%