Raya buys a van for £8,500 x 1.2 = £10,200. Total of 12 equal payments = 12 x £531.25 = £6375. Raya's deposit = £10,200 - £6375 = £3825. Ratio of the deposit Raya pays : Total of the 12 equal payments = 3825:6375. Simplest form (you must divide by highest common factor) --> first try dividing by 25 = 153:255. Second try dividing by 3 = 51:85. 3x25 = 75 = highest common factor so 51:85 is the simplest ratio.