30÷7=4, and the remaining 2.

Four cars are full, and 1 car has only two people.

Law of division:

Operational properties of division

1, the dividend is enlarged (reduced) by n times, and the quotient is correspondingly enlarged (reduced) by n times under the condition that the divisor is unchanged.

2. The divisor is expanded (reduced) by n times, while the dividend is unchanged, and the quotient is correspondingly reduced (expanded) by n times.

3. Dividing the dividend by two divisors is equal to dividing by the product of these two divisors.

Partial correlation formula:

1, dividend = quotient

2. Dividend = divisor

3, divisor × quotient = dividend

4. Divider = (dividend-remainder) quotient

5, quotient = (dividend-remainder) ÷ divisor