The answer process is as follows:
The average person on a big ship is 30÷6=5 yuan.
Per capita ship 24÷4=6 yuan.
So they all arrange big ships.
But it's best not to have empty seats, that is, to make full use of them.
There are 4 big boats and 2 small boats, and the seats are just right, which is the most economical:
4×30+2×24= 168 yuan
So renting four big boats and two small boats is the most economical.
Extended data
Integer addition rule
The same numbers are aligned from the low order. When the numbers add up to ten, they will advance to the previous number.
Integer multiplication rule
(1) From the right, multiply the first factor by the number on each bit of the second factor, and the end of the number will be aligned with which bit of the second factor;
(2) Then add up the numbers multiplied several times. (Multiply with 0 at the end of an integer: you can multiply the number before 0 first, then see how many zeros are at the end of each factor, and add a few zeros at the end of the multiplied number. )