Square polystyrene tiles 50cm by 50cm are used to cover the ceiling of a classroom measuring 7.4m by 4.5m I.find the number of tiles that are needed ii find the cost of $130 per tile

1. Number of tiles * area of 1 tile = area of ceiling = $$ x\cdot0.5\cdot0.5=7.4\cdot4.5 $$ implies $$ x $$ = 133.2 which in whole number will be 133+1 = 134 2. Cost = 134*130 = $17420