Questions are taken verbatim from the NCERT textbook; answers were grounded against the chapter's content during generation. Items needing review are marked.
Your Progress - Chapter 20% complete
1Exercise 2.21 questions
Q.1-81. Find: (i) $\frac{1}{4}$ of (a) $\frac{1}{4}$ (b) $\frac{3}{5}$ (c) $\frac{4}{3}$ (ii) $\frac{1}{7}$ of (a) $\frac{2}{9}$ (b) $\frac{6}{5}$ (c) $\frac{3}{10}$
2. Multiply and reduce to lowest form (if possible): (i) $2\frac{2}{3}\times\frac{2}{3}$ (ii) $\frac{2}{7}\times\frac{7}{9}$ (iii) $\frac{3}{8}\times\frac{6}{4}$ (iv) $\frac{9}{5}\times\frac{3}{5}$ (v) $\frac{1}{3}\times\frac{15}{8}$ (vi) $\frac{11}{2}\times\frac{3}{10}$ (vii) $\frac{4}{5}\times\frac{12}{7}$
3. Multiply the following fractions: (i) $5\frac{1}{4}\times\frac{2}{5}$ (ii) $6\frac{2}{5}\times\frac{7}{9}$ (iii) $2\frac{3}{5}\times\frac{1}{3}$ (iv) $6\frac{5}{7}\times\frac{3}{2}$ (v) $5\frac{2}{7}\times3\frac{4}{5}$ (vi) $3\frac{3}{5}\times\frac{2}{3}$ (vii) $3\frac{4}{5}\times3\frac{3}{7}$
4. Which is greater: (i) $\frac{2}{7}$ of $\frac{3}{4}$ or $\frac{3}{5}$ of $\frac{5}{8}$ (ii) $\frac{1}{2}$ of $\frac{6}{7}$ or $\frac{2}{3}$ of $\frac{3}{7}$
5. Saili plants 4 saplings, in a row, in her garden. The distance between two adjacent saplings is $\frac{3}{4}$ m. Find the distance between the first and the last sapling.
6. Lipika reads a book for $1\frac{3}{4}$ hours everyday. She reads the entire book in 6 days. How many hours in all were required by her to read the book?
7. A car runs 16 km using 1 litre of petrol. How much distance will it cover using $2\frac{3}{4}$ litres of petrol.
8. (a) (i) Provide the number in the box, such that $\frac{2}{3}\times\Box=\frac{10}{30}$. (ii) The simplest form of the number obtained is _____. (b) (i) Provide the number in the box, such that $\frac{3}{5}\times\Box=\frac{24}{75}$. (ii) The simplest form of the number obtained is _____.v
SolutionFor Q5, four saplings create three gaps, so distance $=3\times\frac{3}{4}=\frac{9}{4}=2\frac{1}{4}$ m. For Q6, $6\times1\frac{3}{4}=6\times\frac{7}{4}=10\frac{1}{2}$ hours. For Q7, distance $=16\times2\frac{3}{4}=16\times\frac{11}{4}=44$ km.
Answer:1. (i) (a) $\frac{1}{16}$ (b) $\frac{3}{20}$ (c) $\frac{1}{3}$ (ii) (a) $\frac{2}{63}$ (b) $\frac{6}{35}$ (c) $\frac{3}{70}$.
2. (i) $1\frac{7}{9}$ (ii) $\frac{2}{9}$ (iii) $\frac{9}{16}$ (iv) $\frac{27}{25}$ or $1\frac{2}{25}$ (v) $\frac{5}{8}$ (vi) $1\frac{13}{20}$ (vii) $1\frac{13}{35}$.
3. (i) $2\frac{1}{10}$ (ii) $4\frac{44}{45}$ (iii) $\frac{13}{15}$ (iv) $10\frac{1}{14}$ (v) $20\frac{33}{35}$ (vi) $2\frac{2}{5}$ (vii) $13\frac{1}{35}$.
4. (i) $\frac{3}{5}$ of $\frac{5}{8}$ is greater. (ii) Both are equal, $\frac{3}{7}$.
5. $2\frac{1}{4}$ m.
6. $10\frac{1}{2}$ hours.
7. 44 km.
8. (a) (i) $\frac{5}{10}$ (ii) $\frac{1}{2}$ (b) (i) $\frac{8}{15}$ (ii) $\frac{8}{15}$.
2Exercise 2.31 questions
Q.1-41. Find: (i) $12\div\frac{3}{4}$ (ii) $14\div\frac{5}{6}$ (iii) $8\div\frac{7}{3}$ (iv) $4\div\frac{8}{3}$ (v) $3\frac{1}{2}\div\frac{3}{3}$ (vi) $3\frac{4}{7}\div\frac{5}{3}$
2. Find the reciprocal of each of the following fractions. Classify the reciprocals as proper fractions, improper fractions and whole numbers. (i) $\frac{3}{7}$ (ii) $\frac{5}{8}$ (iii) $\frac{9}{7}$ (iv) $\frac{6}{5}$ (v) $\frac{12}{7}$ (vi) $\frac{1}{8}$ (vii) $\frac{1}{11}$
3. Find: (i) $\frac{2}{3}\div7$ (ii) $\frac{5}{9}\div4$ (iii) $\frac{7}{13}\div6$ (iv) $3\frac{1}{3}\div4$ (v) $2\frac{3}{4}\div3\frac{1}{2}$ (vi) $7\frac{3}{7}\div7\frac{4}{7}$
4. Find: (i) $\frac{2}{5}\div\frac{1}{2}$ (ii) $\frac{4}{9}\div\frac{2}{3}$ (iii) $\frac{3}{7}\div\frac{8}{7}$ (iv) $2\frac{1}{3}\div3\frac{3}{5}$ (v) $3\frac{1}{2}\div\frac{2}{8}$ (vi) $1\frac{2}{5}\div\frac{1}{2}$ (vii) $3\frac{1}{5}\div1\frac{2}{3}$ (viii) $1\frac{1}{5}\div1\frac{1}{5}$v
SolutionDivide by a fraction by multiplying by its reciprocal: $a\div\frac{b}{c}=a\times\frac{c}{b}$. Convert mixed fractions to improper fractions first.
Answer:1. (i) 16 (ii) $\frac{84}{5}$ (iii) $\frac{24}{7}$ (iv) $\frac{3}{2}$ (v) $\frac{9}{7}$ (vi) $\frac{7}{5}$.
2. (i) $\frac{7}{3}$, improper fraction (ii) $\frac{8}{5}$, improper fraction (iii) $\frac{7}{9}$, proper fraction (iv) $\frac{5}{6}$, proper fraction (v) $\frac{7}{12}$, proper fraction (vi) $8$, whole number (vii) $11$, whole number.
3. (i) $\frac{2}{21}$ (ii) $\frac{5}{36}$ (iii) $\frac{7}{78}$ (iv) $\frac{5}{6}$ (v) $\frac{11}{14}$ (vi) $\frac{13}{14}$.
4. (i) $\frac{4}{5}$ (ii) $\frac{2}{3}$ (iii) $\frac{3}{8}$ (iv) $\frac{35}{54}$ (v) $14$ (vi) $\frac{14}{5}$ (vii) $\frac{48}{25}$ (viii) $1$.
3Exercise 2.41 questions
Q.1-51. Find: (i) $0.2\times6$ (ii) $8\times4.6$ (iii) $2.71\times5$ (iv) $20.1\times4$ (v) $0.05\times7$ (vi) $211.02\times4$ (vii) $2\times0.86$
2. Find the area of rectangle whose length is 5.7 cm and breadth is 3 cm.
3. Find: (i) $1.3\times10$ (ii) $36.8\times10$ (iii) $153.7\times10$ (iv) $168.07\times10$ (v) $31.1\times100$ (vi) $156.1\times100$ (vii) $3.62\times100$ (viii) $43.07\times100$ (ix) $0.5\times10$ (x) $0.08\times10$ (xi) $0.9\times100$ (xii) $0.03\times1000$
4. A two-wheeler covers a distance of 55.3 km in one litre of petrol. How much distance will it cover in 10 litres of petrol?
5. Find: (i) $2.5\times0.3$ (ii) $0.1\times51.7$ (iii) $0.2\times316.8$ (iv) $1.3\times3.1$ (v) $0.5\times0.05$ (vi) $11.2\times0.15$ (vii) $1.07\times0.02$ (viii) $10.05\times1.05$ (ix) $101.01\times0.01$ (x) $100.01\times1.1$v
SolutionFor decimal multiplication, multiply as whole numbers and place the decimal according to the total number of decimal places. Q2: area $=5.7\times3=17.1\text{ cm}^2$. Q4: distance $=55.3\times10=553$ km.
Answer:1. (i) 1.2 (ii) 36.8 (iii) 13.55 (iv) 80.4 (v) 0.35 (vi) 844.08 (vii) 1.72.
2. $17.1\text{ cm}^2$.
3. (i) 13 (ii) 368 (iii) 1537 (iv) 1680.7 (v) 3110 (vi) 15610 (vii) 362 (viii) 4307 (ix) 5 (x) 0.8 (xi) 90 (xii) 30.
4. 553 km.
5. (i) 0.75 (ii) 5.17 (iii) 63.36 (iv) 4.03 (v) 0.025 (vi) 1.68 (vii) 0.0214 (viii) 10.5525 (ix) 1.0101 (x) 110.011.
4Exercise 2.51 questions
Q.1-61. Find: (i) $0.4\div2$ (ii) $0.35\div5$ (iii) $2.48\div4$ (iv) $65.4\div6$ (v) $651.2\div4$ (vi) $14.49\div7$ (vii) $3.96\div4$ (viii) $0.80\div5$
2. Find: (i) $4.8\div10$ (ii) $52.5\div10$ (iii) $0.7\div10$ (iv) $33.1\div10$ (v) $272.23\div10$ (vi) $0.56\div10$ (vii) $3.97\div10$
3. Find: (i) $2.7\div100$ (ii) $0.3\div100$ (iii) $0.78\div100$ (iv) $432.6\div100$ (v) $23.6\div100$ (vi) $98.53\div100$
4. Find: (i) $7.9\div1000$ (ii) $26.3\div1000$ (iii) $38.53\div1000$ (iv) $128.9\div1000$ (v) $0.5\div1000$
5. Find: (i) $7\div3.5$ (ii) $36\div0.2$ (iii) $3.25\div0.5$ (iv) $30.94\div0.7$ (v) $0.5\div0.25$ (vi) $7.75\div0.25$ (vii) $76.5\div0.15$ (viii) $37.8\div1.4$ (ix) $2.73\div1.3$
6. A vehicle covers a distance of 43.2 km in 2.4 litres of petrol. How much distance will it cover in one litre of petrol?v
SolutionWhen dividing by 10, 100 or 1000, shift the decimal point left by 1, 2 or 3 places. For Q6, distance per litre $=43.2\div2.4=18$ km.
Answer:1. (i) 0.2 (ii) 0.07 (iii) 0.62 (iv) 10.9 (v) 162.8 (vi) 2.07 (vii) 0.99 (viii) 0.16.
2. (i) 0.48 (ii) 5.25 (iii) 0.07 (iv) 3.31 (v) 27.223 (vi) 0.056 (vii) 0.397.
3. (i) 0.027 (ii) 0.003 (iii) 0.0078 (iv) 4.326 (v) 0.236 (vi) 0.9853.
4. (i) 0.0079 (ii) 0.0263 (iii) 0.03853 (iv) 0.1289 (v) 0.0005.
5. (i) 2 (ii) 180 (iii) 6.5 (iv) 44.2 (v) 2 (vi) 31 (vii) 510 (viii) 27 (ix) 2.1.
6. 18 km.