Paul is painting a wall. He knows the area of the wall is 1920 square metres, correct to the nearest ten. He uses tins of paint, each of which can cover 18 square metres, correct to the nearest integer. He needs to paint the wall completely, and still have at least half a tin of paint left over for any minor repairs. What is the smallest number of tins he must buy to be sure of having enough paint?
UKMT Senior Kangaroo, 2022
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