Exercise 1.3 Solutions – Class X Mathematics
These solutions are based on the Telangana State Class X Mathematics textbook, focusing on decimal expansions and rational numbers. Mathematical expressions are rendered using MathJax.
1. Write the following rational numbers in their decimal form and also state which are terminating and which are non-terminating, repeating decimal.
(i) \( \frac{3}{8} \)
Decimal = 0.375, Terminating
(ii) \( \frac{229}{400} \)
Decimal = 0.5725, Terminating
(iii) \( \frac{4}{5} \)
Decimal = 0.8, Terminating
(iv) \( \frac{2}{11} \)
Decimal = 0.\overline{18}, Non-terminating repeating
(v) \( \frac{8}{125} \)
Decimal = 0.064, Terminating
2. Without performing division, state whether the following rational numbers will have a terminating decimal form or a non-terminating, repeating decimal form.
A rational number \( \frac{p}{q} \) (in lowest form) has a terminating decimal if \( q = 2^m \times 5^n \), where \( m \) and \( n \) are non-negative integers.
(i) \( \frac{13}{3125} \)
Terminating
(ii) \( \frac{15}{16} \)
Terminating
(iii) \( \frac{23}{2^3 \cdot 5^2} \)
Terminating
(iv) \( \frac{7218}{3^2 \cdot 5^2} \)
Non-terminating repeating
(v) \( \frac{143}{110} \)
Non-terminating repeating
(vi) \( \frac{23}{2^3 \cdot 5^2} \)
Terminating
(vii) \( \frac{129}{2^2 \cdot 5^2 \cdot 7^2} \)
Non-terminating repeating
(viii) \( \frac{9}{15} \)
Non-terminating repeating
(ix) \( \frac{36}{100} \)
Terminating
(x) \( \frac{77}{210} \)
Non-terminating repeating
3. Write the following rationals in decimal form using Theorem 1.4.
(i) \( \frac{13}{25} \)
Decimal = 0.52
(ii) \( \frac{15}{16} \)
Decimal = 0.9375
(iii) \( \frac{23}{2^3 \cdot 5^2} \)
Decimal = 0.115
(iv) \( \frac{7218}{3^2 \cdot 5^2} \)
Decimal = 32.08\overline{…}, Non-terminating repeating
(v) \( \frac{143}{110} \)
Decimal = 1.3\overline{…}, Non-terminating repeating
4. Express the following decimals in the form of \( \frac{p}{q} \), and write the prime factors of \( q \). What do you observe?
(i) 43.123
Form = \(\frac{43080}{999}\), Prime factors of \( q = 3^3 \times 37\)
(ii) 0.1201201
Form = \(\frac{4}{33}\), Prime factors of \( q = 3 \times 11\)
(iii) 43.12
Form = \(\frac{1423}{33}\), Prime factors of \( q = 3 \times 11\)
(iv) 0.63
Form = \(\frac{7}{11}\), Prime factors of \( q = 11\)











