A school organized students to travel abroad during the "Eleventh" period. If you use more than 45-seat buses alone, it will be full. If you rent a 60-seat bus alone,

The first question: the design needs X 45 buses, which are just full.

Equation: 45x=60*(x- 1)-30. If you want six 45-seat buses, 270 students can travel abroad.

Second question: It is known that the total number of car rentals is less than 45, that is,

6- 1=5

Let's find out how many 45 buses have been rented. Let's assume that 45 buses have rented X buses.

45x+60(5-x)=270，x=2。 It is found that we should rent two 45-seat buses and three 60-seat buses to minimize the rent.