Answer:
6 drinks
Explanation:
Let the number of drinks each of them drank last year be x. Now the total amount of drink they drank is 3 × x = 3x.
The total amount of drink brought is
3x + 6.
This year they brought the same number of drinks I.e 3x + 6. They still drank same number each as at last year.
This means each also drank x again. Now the total number of drinks drank this year is 2 ×x = 2x.
The total drinks brought however is the addition with the left over. This means total drinks brought this year is 2x + 12
Since the drinks brought last year equals drinks brought this year, this mean:
2x + 12 = 3x + 6
By rearranging, we find x = 6