The DAV Class 7 Maths Solutions and DAV Class 7 Maths Chapter 4 Worksheet 2 Solutions of Application of Percentage offer comprehensive answers to textbook questions.
DAV Class 7 Maths Ch 4 WS 2 Solutions
Question 1.
Find the reciprocals of the following:
(i) (12)5
Answer:
Reciprocal of (12)5
= \(\frac{1}{(12)^5}=\left(\frac{1}{12}\right)^5\)
(ii) (-9)4
Answer:
Reciprocal of (-9)4
= \(\frac{1}{(-9)^4}=\left(-\frac{1}{9}\right)^4\)
(iii) \(\left(\frac{2}{7}\right)^3\)
Answer:
Reciprocal of \(\left(\frac{2}{7}\right)^3\)
= \(\frac{1}{\left(\frac{2}{7}\right)^3}=\left(\frac{7}{2}\right)^3\)
(iv) \(\left(\frac{-3}{7}\right)^7\)
Answer:
Reciprocal of \(\left(\frac{-3}{7}\right)^7\)
= \(\frac{1}{\left(\frac{-3}{7}\right)^7}=\left(\frac{-7}{3}\right)^7\)
(v) \(\left(\frac{-1}{15}\right)^8\)
Answer:
Reciprocal of \(\left(\frac{-1}{15}\right)^8\)
= \(\frac{1}{\left(\frac{-1}{15}\right)^8}\)
= (-15)8
(vi) \(\left(\frac{-8}{13}\right)^{99}\)
Answer:
Reciprocal of \(\left(\frac{-8}{13}\right)^{99}\)
= \(\frac{1}{\left(\frac{-8}{13}\right)^{99}}=\left(\frac{-13}{8}\right)^{99}\)
(vii) \(\left(\frac{1}{10}\right)^{10}\)
Answer:
Reciprocal of \(\left(\frac{1}{10}\right)^{10}\)
= \(\frac{1}{\left(\frac{1}{10}\right)^{10}}=(10)^{10}\)
(viii) \(\frac{2}{3} \times \frac{9}{4}\)
Answer:
Reciprocal of \(\frac{2}{3} \times \frac{9}{4}\)
= \(\frac{1}{\frac{2}{3} \times \frac{9}{4}}=\frac{1}{\frac{18}{12}}\)
= \(\frac{12}{18}=\frac{2}{3}\)
(ix) \(\left(\frac{1}{2}\right)^2\) × 4
Answer:
Reciprocal of \(\left(\frac{1}{2}\right)^2\) × 4
= (2)2 × \(\frac{1}{4}\)
= 4 × \(\frac{1}{4}\)
= 1
(x) \(-\left(\frac{7}{8}\right)^2\)
Answer:
Reciprocal of \(-\left(\frac{7}{8}\right)^2\)
= \(-\frac{1}{\left(\frac{7}{8}\right)^2}=-\left(\frac{8}{7}\right)^2\)