A.25
Work:
-5x-5=25
Hope his helps.
Answer:
160
Step-by-step explanation:
15% + 5% = 20%
80%=0.8
200x0.8=160
Answer: rate of train A = 120 km/h
rate of train B = 101 km/h
Step-by-step explanation:
Let x = the speed of train A
Let y = the speed of train B
One train travels 19 km/h slower than the other. Let train B be the slower train. Therefore,
x = y + 19 - - - - - - - - - -1
Recall
Speed = distance/time
Distance = speed × time
If they meet in 3 hours, it means that train A has travelled a distance of
x × 3 = 3x km
And train B has travelled a distance of y × 3 = 3y km
Train A and Train B were 663 kilometers apart when they left their respective destinations. They left at the same time and travelled towards each other. This means that if they meet in 3hours time, they must have covered a total of 663 km. Therefore,
3x + 3y = 663 - - - - - - - - - 2
Substituting x = y + 19 into equation 2, it becomes
3(y + 19) + 3y = 663
3y + 57 + 3y = 663
6y + 57 = 663
6y = 663 - 57 = 606
y = 606/6 = 101 km/h
x = y + 19 = 101 + 19
x = 120 km/h
