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.
Please provide an image or other when you ask a question, as you’re not gonna get a clear answer
28(7) + 30(25) = 946 square inches
hope this helps!!
Answer: Each notebook costs $2.25. (6p = $13.50)
Step-by-step explanation:
You simply have to divide $13.50 by 6 to get the quotient of $2.25. $2.25 indicates the unit rate between the two.