Mitchell’s dog is 1/3 as old as Katie’s cat. The sum of their ages is 12 years. How old is Mitchell’s dog?

Mitchell's dog is 3 years old

Step-by-step explanation:

9 x 1/3 = 3

9 + 3 = 12

To solve this I just thought of the multiples of three under 12 that if added to 3 are equal to 12 to find Katie's cat age. The multiples of three under 12 are 3, 6 and 9. It couldn't be 3 and 6+3=9 so it had to be 9. So if Katie's cat is 9, you just multiply 9 by 1/3 or divide it by 3 to find Mitchell's dog age.

85.560%

step-by-step explanation:

conditional probability is defined as:

p(a|b) = p(a∩b) / p(b)

in other words, the probability that a occurs, given that b has occurred = the probability that both a and b occur / the probability that b occurs.

in this example:

p(turns 64 | turns 44) = p(turns 64 & turns 44) / p(turns 44).

if someone turns 64, they must have already turned 44, so:

p(turns 64 | turns 44) = p(turns 64) / p(turns 44)

on page 42, we see that of the original 100,000, 94944 turn 44, and 81234 turn 64.   therefore:

p(turns 64 | turns 44) = 81234 / 94944

p(turns 64 | turns 44) = 0.85560