Minesh wrote:

before you ask why we are doing them - this is what set for hwk - any thoughts please

Tickets for a school play cost £3 for adults and £1 for children. The total amount collected from ticket sales was £1320. The play was staged in a hall seating 600 but the hall was not completely full. What was the smallest possible number of adults at the play?

358, 359, 360, 361, 362

Alternatively, you could work back from the answers offered:

358 adults means 1320-3*358 = 246 children, total 604 (overfull)

359 adults means 1320-3*359 = 243 children, total 602 (overfull)

360 adults means 1320-3*360 = 240 children, total 600 (completely full)

361 adults means 1320-3*361 = 237 children, total 598 (not completely full)

362 adults means 1320-3*362 = 234 children, total 596 (not completely full)

so 361 is the smallest possible.