Answer:
66
Step-by-step explanation:
If there are <em>n</em> students, then the number of pairs is
.
With 12 students,
pairs can be formed.
The reason the formula works is this: Each of the 12 students can be paired with 11 other students (no student is paired with him/her self). But counting 12 x 11 = 132 counts each pair <u>twice</u>. Example: student A can be paired with student B,..., student B can be paired with student A. The pair was counted two times.
See the attached image that shows pairings of 5 students. There are
5(5 - 1)/2 = 5(4)/2 = 10 pairs.
What????
You just add 1 +3 =4
Answer:
Transitive Property
Step-by-step explanation:
Since X is the midpoint, it bisects the points RS. If MX=XS, and RS is the same as XS, then they are the same. This also follows the Transitive propety (if a=b and b=c, then a=c)