Answer:
20 possible arrangements
Step-by-step explanation:
A: Alice
B: Bob
C: Cindy
X: other student
All the possible arrangements are:
When Bob is in the first place
B A C X X
B A X C X
B A X X C
B X A C X
B X A X C
B X X A C
6 possible arrangements
When Bob is in the second place (notice that neither Alice nor Cindy can be before Bob)
X B A C X
X B A X C
X B X A C
3 possible arrangements
When Bob is in the third place
X X B A C
Only 1 possible arrangement.
Total arrangements when Bob is before Cindy: 10
If Cindy is before Bob the same situations are repeated, given another 10 arrangements. So, the total line up in which Alice is somewhere between Bob and Cindy are 20.
The minimum speed will be calculated as follows:
Time taken from Toledo to Elkhart=(8.15-5.45)=2 1/2 hours
Distance=136 miles
thus the speed between Toledo and Elkhart= 136 miles/2.5=54.4 mph
Distance between Toledo and Chicago is 244 miles
Distance between Elkhart and Chicago=244-136=108 miles
time taken to travel between Elkhart and Chicago assuming that I left Elkhart at exactly 8:15 and reach at 10.30:
=10:30-8:15=2.25 hours
thus the speed will be:
speed=(108)/(2.25)=48 mph
Thus for us to get to Chicago by 10:30 a.m we should drive at 48 mph
We are asked to identify an another way to solve the given problem or this summation 104 + 34 + 228 + 887. We can verify it by doing of performing the summation in a reverse sequence such 877 comes first, then followed by 228, then followed by 34 and lastly added by 104. Therefore, the answer is 877 + 228 + 34 + 104.This is an another way to solve the given problem.
