7. Allan went shopping for stationery. He bought x pens at $1.75 each and y books at $2.50 each.
(a) How much money, in dollars, in terms of x and y, did Allan spend altogether?​

$4.25

Step-by-step explanation:

x pens=$1.75

y pens =$2.50

Now,

in the terms of x and y ,

Alan spend altogether=1.75 +2.50

=$4.25

21/58.

hope to be marked brainliest

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