Determine if the following ratios form a proportion. Also, write the middle terms and extreme terms where the ratios form a proportion.(a) 25 cm : 1 m and Rs 40 : Rs 160 (b) 39 litres : 65 litres and 6 bottles : 10 bottles(c) 2 kg : 80 kg and 25 g : 625 g    (d) 200 ml : 2.5 litre and Rs 4 : Rs 50