Is there a mistake? The school organizes a spring outing. If you rent more than 45-seat buses, they are just full. If you rent a 60-seat bus, you will lose 1 bus and gain 30 seats. If you want to rent a 45-seat bus from 250 yuan and a 60-seat bus from 300 yuan, you must rent two cars together, which is cheaper than renting a single bus, with 45 seats less than 60 seats (less). How much does this car rental plan cost?

Rent more than 45-seat buses, just full.

There are x 45 buses.

45X=60(X- 1)-30

X=6

There are 45*6=270 people.

When two kinds of cars must be rented together, 45 cars have Y cars and 60 cars have Y+ 1 car.

45Y+60(Y+ 1)=270

Y=2 10/ 105

So Y=2.

This car rental scheme needs 250*2+300*3= 1400 yuan.