Sela is making 400 scones.
she use butter ,sugar and flour in the ratio 2:1:9
here the cost of those ingredients
butter-2.50 per 500g
sugar-1.60 per kilogram
flour-60p per 1.5kg
the total mass of the butter ,sugar and flour in each scone is 30g
work out the total cost of these ingredients for the 400
scones