The browns are moving across the counrty. Mr. Brown leaves 2.5 hours before Mrs. Brown, if he averages 75 mph and she averages 85 mph, how many hours will it take Mrs. Brown to catch up to Mr. Brown?

the time taken by Mrs Brown to catch up is 18.75 hours

Step-by-step explanation:

Given;

average speed of Mr Brown = 75 mph

average speed of Mrs Brown, = 85 mph

time first traveled by Mr Brown = 2.5 hours

The distance traveled by Mr Brown before Mrs Brown start her own Journey;

D = speed  x time

D = 75 mph x 2.5 h

D = 187.5 miles

Let the time taken by Mrs Brown to catch up = t

(85 - 75)t = 187.5

10t = 187.5

t = 18.75 hours

Check:

after 18.75 hours:  Mrs Brown will travel ⇒ 18.75 x 85 = 1593.75 miles

after (2.5 h + 18.75h) : Mr Brown will travel ⇒ 21.25 x 75 = 1593.75 miles

a = 3.14

b = 18

c = 18/5 or 3.6 or 3 3/5

step-by-step explanation:

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