Atrain travels 68 km at an average speed of 51 km/h. it then travels another 20 km at an average speed of 40 km/h before reaching its destination. calculate the average speed for the whole journey. also give the solution of this problem.

time = distance / rate

travelling 68 km at 51 km/hour = 1 + (1/3) hours

travelling 20 km at 40 km/hour = .50 hours

total time = 1.8333333... hours

total distance = 68 + 20 = 88 kilometers

average speed = 88 km / 1.8333333... hours

average speed = 48 km / hour

x=-2

infinite number of lines, so there is an infinite number of equations.

step-by-step explanation:

there are an infinite number of line that passes through the point (-2,5)

x=-2   is one line that passes through the point

y = 5 is another line that passes through the point

(these two lines are perpendicular to each other).

since the number of   numbers are infinite and the slope is the ratio of two numbers,(change in y over change in x) we can have an infinite number of slopes.     our only condition is that it passes through the point (-2,5)

the answer is 21%.