Jamie and Oliver will spend $24 x 2 = $<<24*2=48>>48 for the plane ticket.
They will spend $12 x 2 = $<<12*2=24>>24 for staying in the hotel per day.
So, the total amount they will spend on the hotel for a 3-day stay is $24 x 3 = $<<24*3=72>>72.
Therefore, the total amount they will spend on their vacation is $72 + $48 = $<<72+48=120>>120.
#### 120