a plane has 360 total seats, which are divided into economy class and business class. For every 13 seats in economy class, there are 5 seats in business class
ok so out of 18 seats 13 are economy and 5 are business and since 18 times 20 is 360 we multiply each of these by 20 so 13 times 20 is 260 20 times 5 is 100 there you go
