A cyclist traveled for two days. On the second day the cyclist traveled 4 hours longer and at an average speed 10 mile per hour slower than she traveled on the first day. If during the two days she traveled a total of 210 miles and spent a total of 12 hours traveling, what was her average speed on the second day?	Select:
A) 5 mph
B) 10 mph
C) 20 mph
D) 30 mph
E) 40 mph
SOLUTION:   D = 280 Mi   T = 12 hrs   Day 1 time = T1   Day 2 time = T2   T2 - T1 = 4 hrs ----- (I)   T1 + T2 = 12 hrs ----- (II)   Adding I and II, T2 = 8 hrs and T1 = 4 hrs   Day 1 Rate = R1   Day 2 Rate = R2   R1 - R2 = 10 mph   i.e. R1 = 10 + R2   280 = 8R2 + 4R1   i.e. 280 = 8R2 + 4 (10 + R2)   i.e. R2 = 20 mph   ANSWER: 30 mph
<result>D</result>
A cyclist traveled for two days. On the second day the cyclist traveled 4 hours longer and at an average speed 10 mile per hour slower than she traveled on the first day. If during the two days she traveled a total of 210 miles and spent a total of 12 hours traveling, what was her average speed on the second day?