It is the second one down
Step-by-step explanation:
I think there's an easy way and a hard way to do this, and I think that the way
I'm about to describe is the easier way.
Probability = (number of successful outcomes)/(total number of possible outcomes)
<em>How many total pairs can be drawn from 8 total pens ?</em>
-- The first one drawn can be any one of 8 pens. For each of these . . .
-- The second one drawn can be any one of the remaining 7 .
-- Total number of ways of drawing a pair = (8 x 7) = 56 ways.
-- But there aren't 56 different different pairs. Whether you draw A and then B,
or B and then A, you wind up with the same pair. There are 2 different ways to
draw each pair, so the 56 ways of drawing a pair only produces <u>28</u> different pairs.
<u>How many pairs are two of the same color ?</u>
<em>Possible number of blue pairs:</em>
The reasoning is exactly the same as calculating the TOTAL number of
pairs, as explained above.
With 5 blue pens, you can make <u>10</u> different pairs.
AB, AC, AD, AE, BC, BD, BE, CD, CE, and DE.
<em>Possible number of red pairs:</em>
The reasoning is exactly the same as calculating the TOTAL number of
pairs, as explained above.
With 3 red pens, you can make <u>3</u> different pairs.
AB, AC, and BC.
Total number of possible same-color pairs = 10 + 3 = 13
successes / total possible outcomes = 13/28 = <u>46.4</u>% (rounded)
Answer:
Speed of passenger train=18+30=48 mph
Speed of freight train=30 mph
Step-by-step explanation:
Let x be the speed of freight train.
Speed of passenger train=x+18 mph
Time taken by freight train=1.5+2.5=4 hrs
Time taken by passenger train to overtake the freight train=2.5 hrs
Distance=
By using this formula
Distance traveled by passenger train=2.5(x+18) miles
Distance traveled freight train=4x
According to question
Speed of freight train=30 mph
Speed of passenger train=18+30=48 mph
