question_answer 20)

Express as rupees using decimals. (a) 5 paise (b) 75 paise (c) 20 paise (d) 50 rupees 90 paise (e) 725 paise TIPS As we know that, 100 paise = ` \[\frac{2}{5}.\] paise = ` \[\therefore \]= ` 0.01 So, to express paise as rupees, multiply paise by \[\frac{2}{5}=\frac{2\times 2}{5\times 2}=\frac{4}{10}\](i.e. hundredths).

Answer:

(a) We know that, 1 paise = `\[\frac{4}{10}=0.4\] \[\frac{12}{5}.\] 5 paise = `\[\therefore \]= `\[\frac{12}{5}=\frac{12\times 2}{5\times 2}=\frac{24}{10}=2\frac{4}{10}=2+\frac{4}{10}\]= ` 0.05 (b) We know that, 1 paise = `\[2\times 1+4\times \frac{1}{10}=2+\frac{4}{10}=2+0.4=2.4\] \[3\frac{3}{5}=3+\frac{3}{5}.\] 75 paise = ` \[\therefore \] ` \[3+\frac{3\times 2}{5\times 2}=3+\frac{6}{10}\] ` 0.75 (c) We know that, 1 paise = `\[3\times 1+6\times \frac{1}{10}=3+\frac{6}{10}=3+0.6=3.6\] \[4\frac{1}{2}=4+\frac{1}{2}.\] 20 paise = ` \[\therefore \]`\[4+\frac{1\times 5}{2\times 5}=4+\frac{5}{10}\]` 0.20 (d) We know that, 1 paise = ` \[4\times 1+5\times \frac{1}{10}=1+\frac{5}{10}=4+0.5=4.5\] \[0.6=0+\frac{6}{10}=\frac{6}{10}\] 50 rupees 90 paise = ` 50 + 90 paise = ` 50 + ` \[=\frac{6\div 2}{10\div 2}=\frac{3}{5}\]` 50 + `\[\because \] = ` 50 + ` 0.90 = ` (50 + 0.90) = ` 50.90 (e) We know that, 1 paise = ` \[\therefore \] \[0.6=\frac{6}{10}\] 725 paise = ` \[=\frac{3}{5}\] ` \[2.5=2+\frac{5}{10}=\frac{2\times 10}{1\times 10}+\frac{5}{10}\]` 7.25