18) B

After baking the cake and making 60 biscuits:

  • Amount of flour left = 1000 – 225 – 400 = 375 g
  • Number of eggs left = 12 – 2 = 10
  • Amount of milk left = 2500 – 250 = 2250 ml
  • Amount of butter = 600 – 150 – 400 = 50 g
  • Amount of sugar = 600 – 330 – 200 = 70 g
  • Number of lemons left = 5

The recipe given is for 8 pancakes. So, we need to divide each of the values by 8.

  • Amount of flour = 100 / 8 = 12.5 g
  • Number of eggs = 2 / 8 = 0.25
  • Amount of milk = 200 / 8 = 25 ml
  • Amount of butter = 50 / 8 = 6.25 g
  • Amount of sugar = 20 / 8 = 2.5 g
  • Number of lemons = 1 / 8 = 0.125

In order to quickly calculate the number of pancakes that can be made, we need to identify which ingredient has the least amount left compared to the amount needed.

In this case, it is the butter. 50 g is left and 6.25 g is needed for 1.

The ratio of amount left : amount needed is higher for other ingredients compared to butter.

Number of pan cakes that can be made with 50 g of butter = 50 / 6.25 = 8