Answer:
43
Step-by-step explanation:
A couple is two.
They have 5 sons which now makes them 7
Each son has 3 sisters and since its the same parents, they will all have 3 sisters, which makes them 10.
It is impossible for all these 3 sisters to have 11 babies together.
So each sister has 11 babies, which makes it 33 babies.
33+10 will give 43.
Therefore 43 people went for the picnic