A different pattern is made using 20 straight lines and 16 arcs. The straight lines and arcs are made of metal. 20 straight lines cost £12 and the cost of one straight line: cost of one arc = 2:3. Work out the total cost of metal in the pattern.

First we need to find the cost of one arc from the information we already have about the arc (20 straight lines cost £12). To do this divide the £12 total cost by the number of lines 20.12 ÷ 20 = £0.60 eachNext we need to find the price of an arc and to do this we must use cross multiplication. Call the price of an arc B.0.6 : X2 : 30.6 x 3 = X x 2therefore X = 0.6 x 3/ 2X = £0.90 eachThe last and final step is to calculate the total cost of metal in the patternWith 20 straight lines each at £0.60 and 16 arcs at £0.90 eachTotal price of 20 straight lines = £0.60 x 20 = £12Total price of 16 arcs = £0.90 x 16 = £14.40Total metal (both straight lines and arcs) = £12 + £14.40 = £26.40ANS: £26.40