The ratio of the number of boys to the number of girls in a choir is 5 to 4. There are 60 girls in the choir. How many boys are in the choir? A 75 B 61 C 48 D 80

75 boys

Step-by-step explanation:

60 / 4 = 15

5 × 15 = 75

4 packs of water and 7 packs of candy bars

step-by-step explanation:

35x4=140

140/20=7

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