Answer:
11 invitations each
Step-by-step explanation:
Let the number of invitations they bought be x .
Since they spent the same amount of money, Their total costs would be the same. Hence ;
3.25 + 0.75(x) = 0.5x + 6
0.75x - 0.5x = 6 - 3.25
0.25x = 2.75
x = 2.75/0.25
x= 11 invitations