He can only pick 7 different groups because 2 times 7 is 14, and there are 15 people in all.
Hope this helps. c:
Answer:

Step-by-step explanation:




Answer:
Step-by-step explanation:




you do your math!!
The number=10x+y
we suggest this system of equations:
(10y+x)-(10x+y)=27
x+y=9 ⇒x=9-y
Can solve this system of equations by susbstitution method.
(10y+(9-y)-(10(9-y)+y)=27
10y+9-y-(90-10y+y)=27
10y-y+10y-y=27-9+90
18y=108
y=108/18
y=6
x=9-y
x=9-6
x=3
The number=10x+y=10(3)+6=36
Answer: the number is 36.
to check:
63-36=27
6+3=9