Answer:
1 hour after 2 weeks
Step-by-step explanation:
She rides 3 days a week, and 10 minutes a day. Multiplying 3 and 10 gets you 30 minutes a week. Over a 2 week period, that is 60 minutes (1 hour)
X= fancy, y= plain
x+y= 7
28x+ 15y=131
solve by substitution
50 Is the answer.........
Let's assume that a,b&c are in one straight line, so cannot form a triangle with each other. Now, total possible Triangle that can be formed choosing any 3 points without any colinear constraint is 8C3 = 56