Answer:
The answer is 36
Step-by-step explanation:
Because right before they served the cake groups of 3 arrived late then after the cake 4 people left, So the 3 groups had 9 of them each of them had 3 people and then there are 4 people left so 3 multiply to 3 is 9 then multiply the answer 9 × 4 = 36, there are 36 people came to the party..