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Last updated at Sept. 26, 2018 by Teachoo

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Ex 12.2, 4 Determine if the following ratios form a proportion. Also, write the middle terms & extreme terms where the ratios form a proportion. (a) 25 cm : 1 m and Rs 40 : Rs 160 1 m = 100 cm Now, 25 cm : 1 m = (25 ๐๐)/(1 ๐) = (25 ๐๐)/(100 ๐๐) = 25/100 = 1/4 = 1 : 4 Rs 40 : Rs 160 = (๐ ๐ 40)/(๐ ๐ 60) = 40/160 = 4/16 = 1/4 = 1 : 4 โด 25 cm : 1 m = Rs 40 : Rs 160 So, given ratios are in a proportion Here, Middle terms = 1 m, Rs 40 Extreme terms = 25 cm, Rs 160 Ex 12.2, 4 Determine if the following ratios form a proportion. Also, write the middle terms & extreme terms where the ratios form a proportion. (b) 39 litres : 65 litres and 6 bottles : 10 bottles39 litres : 65 litres = (39 ๐๐๐ก๐๐๐ )/(65 ๐๐๐ก๐๐๐ ) = 39/65 = 3/5 = 3 : 5 6 bottles : 10 bottles = (6 ๐๐๐ก๐ก๐๐๐ )/(10 ๐๐๐ก๐ก๐๐๐ ) = 6/10 = 3/5 = 3 : 5 โด 39 litres : 65 litres = 6 bottles : 10 bottles So, Given ratios are in proportion Here, Middle terms = 65 litres, 6 bottles Extreme terms = 39 litres, 10 bottles Ex 12.2, 4 Determine if the following ratios form a proportion. Also, write the middle terms & extreme terms where the ratios form a proportion. (c) 2 kg : 80 kg and 25 g : 625 g2 kg : 80 kg = (2 ๐๐)/(80 ๐๐) = 2/80 = 1/40 = 1 : 40 25 g : 625 g = (25 ๐)/(625 ๐) = 25/625 = 5/125 = 1/25 = 1 : 25 โด 2 kg : 80 kg โ 25 g : 625 g So, given ratio are not in proportion Ex 12.2, 4 Determine if the following ratios form a proportion.Also, write the middle terms & extreme terms where the ratios form a proportion. (d) 200 ml : 2.5 litre and Rs 4 :Rs 50 2.5 litres = 2.5 ร 1000 ml = 25/10 ร 1000 ml = 25 ร 100 ml = 2500 ml 200 ml : 2.5 litre ` = (200 ๐๐)/(2.5 ๐๐๐ก๐๐๐ ) = (200 ๐๐)/(2500 ๐๐) = 200/2500 = 2/25 = 2 : 25 Rs 4 : Rs 50 = (๐ ๐ 4)/(๐ ๐ 50) = 4/50 = 2/25 = 2 : 25 โด 200 ml : 2.5 litres = Rs 4 : Rs 50 So, given ratios are in proportion Here, Middle terms = 2.5 litres, Rs 4 Extreme terms = 200 ml, Rs 50

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Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.