Punjab State Board PSEB 7th Class Maths Book Solutions Chapter 2 Fractions and Decimals Ex 2.4 Textbook Exercise Questions and Answers.
PSEB Solutions for Class 7 Maths Chapter 2 Fractions and Decimals Ex 2.4
1. Find the reciprocal of each of the following fraction.
(i) \(\frac {2}{7}\)
(ii) \(\frac {3}{2}\)
(iii) \(\frac {5}{7}\)
(iv) \(\frac {1}{9}\)
(v) \(\frac {2}{3}\)
(vi) \(\frac {7}{8}\)
Answer:
(i) \(\frac {7}{2}\)
(ii) \(\frac {2}{3}\)
(iii) \(\frac {7}{5}\)
(iv) 9
(v) \(\frac {3}{2}\)
(vi) \(\frac {8}{7}\)
2. Solve the following (Division of a fraction by a non zero whole number)
Question (i).
\(\frac {19}{6}\) ÷ 10
Answer:
\(\frac {19}{6}\) ÷ 10
= \(\frac{19}{6} \times \frac{1}{10}\)
= \(\frac {19}{60}\)
Question (ii).
\(\frac {4}{9}\) ÷ 5
Answer:
\(\frac {4}{9}\) ÷ 5
= \(\frac{4}{9} \times \frac{1}{5}\)
= \(\frac {4}{45}\)
Question (iii).
\(\frac {8}{9}\) ÷ 8
Answer:
\(\frac {8}{9}\) ÷ 8
= \(\frac{8}{9} \times \frac{1}{8}\)
= \(\frac {1}{9}\)
Question (iv).
3\(\frac {1}{2}\) ÷ 4
Answer:
3\(\frac {1}{2}\) ÷ 4
= \(\frac{7}{2} \times \frac{1}{4}\)
= \(\frac {7}{8}\)
Question (v).
16\(\frac {1}{2}\) ÷ 5
Answer:
16\(\frac {1}{2}\) ÷ 5
= \(\frac{33}{2} \times \frac{1}{5}\)
= \(\frac {33}{10}\)
= 3\(\frac {3}{10}\)
Question (vi).
4\(\frac {1}{3}\) ÷ 3
Answer:
4\(\frac {1}{3}\) ÷ 3
= \(\frac{13}{3} \times \frac{1}{3}\)
= \(\frac {33}{9}\)
= 1\(\frac {4}{9}\)
3. Solve the following (Division of a whole number by a fraction)
Question (i).
8 ÷ \(\frac {7}{3}\)
Answer:
8 ÷ \(\frac {7}{3}\)
= 8 × \(\frac {3}{7}\)
= \(\frac {24}{7}\)
= 3\(\frac {3}{7}\)
Question (ii).
5 ÷ \(\frac {7}{5}\)
Answer:
5 ÷ \(\frac {7}{5}\)
= 5 × \(\frac {5}{7}\)
= \(\frac {25}{7}\)
= 3\(\frac {4}{7}\)
Question (iii).
4 ÷ \(\frac {8}{3}\)
Answer:
4 ÷ \(\frac {8}{3}\)
= 4 × \(\frac {3}{8}\)
= \(\frac {3}{2}\)
= 1\(\frac {1}{2}\)
Question (iv).
3 ÷ 2\(\frac {3}{5}\)
Answer:
3 ÷ 2\(\frac {3}{5}\)
= 3 ÷ \(\frac {13}{5}\)
= 3 × \(\frac {5}{13}\)
= \(\frac {15}{13}\)
= 1\(\frac {2}{13}\)
Question (v).
5 ÷ 3\(\frac {4}{7}\)
Answer:
5 ÷ 3\(\frac {4}{7}\)
= 5 ÷ 3\(\frac {25}{7}\)
= 5 × \(\frac {7}{25}\)
= \(\frac {7}{25}\)
= 1\(\frac {2}{5}\)
4. Solve the following (Division of a fraction by another fraction)
Question (i).
\(\frac{2}{3} \div \frac{10}{9}\)
Answer:
\(\frac{2}{3} \div \frac{10}{9}\)
= \(\frac{2}{3} \times \frac{9}{10}\)
= \(\frac {3}{5}\)
Question (ii).
\(\frac{4}{9} \div \frac{2}{3}\)
Answer:
\(\frac{4}{9} \div \frac{2}{3}\)
= \(\frac{4}{9} \times \frac{3}{2}\)
= \(\frac {2}{3}\)
Question (iii).
\(2 \frac{1}{2} \div \frac{3}{5}\)
Answer:
\(2 \frac{1}{2} \div \frac{3}{5}\)
= \(\frac{5}{2} \times \frac{5}{3}\)
= \(\frac {25}{6}\)
= 4\(\frac {1}{6}\)
Question (iv).
\(\frac{3}{7} \div 1 \frac{1}{5}\)
Answer:
\(\frac{3}{7} \div 1 \frac{1}{5}\)
= \(\frac{3}{7} \div \frac{6}{5}\)
= \(\frac{3}{7} \times \frac{5}{6}\)
= \(\frac {5}{14}\)
Question (v).
\(5 \frac{1}{2} \div 2 \frac{1}{5}\)
Answer:
\(5 \frac{1}{2} \div 2 \frac{1}{5}\)
= \(\frac{11}{2} \div \frac{11}{5}\)
= \(\frac{11}{2} \times \frac{5}{11}\)
= \(\frac {5}{2}\)
= 2\(\frac {1}{2}\)
Question (vi).
\(3 \frac{1}{5} \div 1 \frac{2}{3}\)
Answer:
\(3 \frac{1}{5} \div 1 \frac{2}{3}\)
\(\frac{16}{5} \div \frac{5}{3}\)
= \(\frac{16}{5} \times \frac{3}{5}\)
= \(\frac {48}{25}\)
= 1\(\frac {23}{25}\)
5. 11 small ropes are cut from 7\(\frac {1}{3}\) m long rope. Find the length of each of the small rope.
Solution:
Length of rope = 7\(\frac {1}{3}\) m = \(\frac {22}{3}\) m,
∴ Length of 11 small ropes = \(\frac {22}{3}\)m
Length of each small rope = \(\frac {22}{3}\)m ÷ 11
= \(\frac{22}{3} \times \frac{1}{11} \mathrm{~m}\)
= \(\frac {2}{3}\)m
6. Multiple choice questions :
Question (i).
Reciprocal of \(\frac {3}{4}\) is :
(a) \(\frac {3}{4}\)
(b) \(\frac {4}{3}\)
(c) 1
(d) none of these
Answer:
(b) \(\frac {4}{3}\)
Question (ii).
\(\frac{5}{7} \div \frac{7}{5}=?\)
(a) 1
(b) \(\frac {49}{25}\)
(c) \(\frac {25}{49}\)
(d) -1
Answer:
(c) \(\frac {25}{49}\)
Question (iii).
\(\frac{5}{7} \div \frac{5}{7}=?\)
(a) 1
(b) \(\frac {49}{25}\)
(c) \(\frac {25}{49}\)
(d) -1
Answer:
(a) 1
7.
Question (i).
The reciprocal of a proper fraction is an improper fraction (True/False)
Answer:
True
Question (ii).
The reciprocal of a whole number is always a whole number (True / False)
Answer:
False.