Two trains running on parallel tracks are 600 miles apart. one train is moving east at a speed of 90 miles per hour, while the other is moving west at 75 miles per hour. how long will it take for the two trains pass each other?

Remark

The trick here is to realize that between them they will cover 600 miles

Train one

r = 90 mph

t = ?? [same for both trains]

d = d1

Train Two

r = 75 miles / hour

t = ?? [same for both trains]

d = d2

Equation.

basically d = r*t

d_train1 + d_train2 = total_distance

90*t + 75*t = 600

Combine and solve

165t = 600 Divide by 165

t = 600/165

t = 3.64 hours <<<<<< Answer

answer set (b) 0.5, 3/4 80% is in order from least to greatest.  

step-by-step explanation:

in order to compare rational numbers to each other, it is much easier if they are in the same form.   typically, the best form in which to evaluate rational numbers is in decimals.   in order to convert a percent to a decimal, you would divide the given percentage by 100.   you can also accomplish the conversion by moving the decimal point over two places to the left.   for example, the decimal value of 80% is 80/100, or 0.8.   in order to convert a fraction to a decimal, you need to divide the numerator by the denominator.   for example, 3/4 is 0.75.   so, for choice (b) 0.5 3/4 (0.75), 80% (0.8) is the only choice in which the numbers are in order from least to greatest.  

m∠a is 90°

m∠b is 40°