If 6 lemons cost 90p how much does 4 cost?

To calculate the cost of 4 lemons, we need to first find the cost of one lemon. To do this, we can divide the total cost of 6 lemons by 6.

Cost of 1 lemon = 90p / 6 = 15p

Therefore, the cost of 4 lemons will be:

Cost of 4 lemons = 4 * 15p = 60p