Decimal Fractions Questions and Answers

This set of Aptitude Questions and Answers (MCQs) focuses on “Decimal Fractions”. These questions are beneficial for various competitive exams, placement interviews, and entrance tests.

1. What is the value of (2.99)2?
a) 8.9401
b) 8.9041
c) 8.4901
d) 8.4491
View Answer

Answer: a
Explanation: (2.99)2 = (3 – 0.01)2 = 32 + 0.012 – 2*3*0.01 = 8.9401.

2. What is the value of \(\sqrt{\frac{0.09*0.0064*0.81*0.049}{0.03*0.0007*0.016*0.21}}\)?
a) 6√3
b) 18
c) 12
d) 24
View Answer

Answer: b
Explanation: \(\sqrt{\frac{0.09*0.0064*0.81*0.049}{0.03*0.0007*0.016*0.21}}=\sqrt{\frac{9*64*81*49}{3*7*16*21}}\)=18.

3. Find the value of \(\frac{0.49-0.25}{0.2}\)?
a) 1.04
b) 1.4
c) 1.02
d) 1.2
View Answer

Answer: d
Explanation: \(\frac{0.49-0.25}{0.2}=\frac{0.7^2-0.5^2}{0.7-0.5}=\frac{(0.7+0.5)(0.7-0.5)}{0.7-0.5}\)=1.2 .
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4. Find the value of \(\frac{0.24*0.24*0.24-0.12*0.12*0.12}{0.72*0.72*0.72-0.36*0.36*0.36}\).
a) 1/9
b) 1/3
c) 1/27
d) 1/21
View Answer

Answer: c
Explanation: \(\frac{0.24*0.24*0.24-0.12*0.12*0.12}{0.72*0.72*0.72-0.36*0.36*0.36} = \frac{0.24^3-0.12^3}{(3*0.24)^3-(3*0.12)^3} =\frac{0.24^3-0.12^3}{27(0.24^3-0.12^3)}=\frac{1}{27}\).

5. Find the value of \(\frac{0.64^3+0.36^3}{0.64^2+0.36^2-0.64*0.36}\).
a) 1
b) 0.28
c) 1.28
d) 1.1
View Answer

Answer: a
Explanation: \(\frac{a^3+b^3}{a^2-ab+b^2}\)=a+b
\(\frac{0.64^3+0.36^3}{0.64^2+0.36^2-0.64*0.36}\)=0.64+0.36=1.

6. Find the value of \(\frac{a^3-b^3}{a^2+ab+b^2}\), for a = 1.1 and b = 0.2.
a) 0.8
b) 0.9
c) 1.3
d) 0.7
View Answer

Answer: b
Explanation:\(\frac{a^3-b^3}{a^2+ab+b^2}\)=a-b=1.1-0.2=0.9.

7. Find the value of \(\frac{0.64^2-0.49^2-0.36^2}{0.064^2-0.049^2-0.036^2}\).
a) 10
b) 1/100
c) 100
d) 1/300
View Answer

Answer: c
Explanation: \(\frac{0.64^2-0.49^2-0.36^2}{0.064^2-0.049^2-0.036^2}=\frac{0.64^2-0.49^2-0.36^2}{(\frac{0.64}{10})^2-(\frac{0.49}{10})^2-(\frac{0.36}{10})^2}\)=100.
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8. Find the value of 0.0813+0.0093+0.002187*0.009.
a) 0.000729
b) 0.00729
c) 0.0000729
d) 0.729
View Answer

Answer: a
Explanation: a3+b3+3ab(a+b) = (a+b)3.
0.0813+0.0093+0.002187*0.009 = 0.0813 + 0.0093 + 3*0.081*0.009(0.081+0.009) = (0.081+0.009)3 = 0.093 = 0.000729.

9. Which of the following is equal to 1?
a) \(\frac{0.21^2}{2.1^2*0.1} \)
b) \(\frac{2.1^2}{21^2*0.01^2} \)
c) \(\frac{0.021^2}{2.1^2*0.01^2} \)
d) \(\frac{0.21^2}{21^2*0.01} \)
View Answer

Answer: c
Explanation: \(\frac{0.021^2}{2.1^2*0.01^2} = \frac{21^2*10^{-6}}{(21^2*10^{-2}*10^{-4}}\)=1.
Hence, \(\frac{0.021^2}{2.1^2*0.01^2}\) is the answer.
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10. Find the value of \(\frac{0.8^2+0.2^2}{0.64^2-0.04^2}\).
a) 1.16
b) 0.16
c) 1.6
d) 0.6
View Answer

Answer: c
Explanation: \(\frac{0.8^2+0.2^2}{0.64^2-0.04^2}=\frac{0.64+0.04}{(0.64+0.04)(0.64-0.04)}=\frac{1}{0.6}\)=1.6.

More Aptitude Questions and Answers on Decimal Fractions:

To practice all aptitude questions, please visit “1000+ Quantitative Aptitude Questions”, “1000+ Logical Reasoning Questions”, and “Data Interpretation Questions”.

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Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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