Let the radius of the sphere be r.
Surface area of sphere = 154
So, \(4\pi r^2 = 154\ cm^2 \)
r2 = \(\frac{154}{4\pi}\)
r2 = \(\left(\frac{154}{4}\right) \left(\frac{7}{22}\right)\)
r2 = \(\frac{\text{(154 × 7) }}{\text{ (4 × 22)}}\)
r2 = \((\frac{49}{4})\)
r = (\(\frac{7}{2}\)) = 3.5 cm
Therefore, the radius of the sphere whose surface area is 154 cm2 is 3.5 cm.
Factorise each of the following:
(i) 27y 3 + 125z 3
(ii) 64m3 – 343n 3
[ Hint : See Question 9. ]
Use these adverbs to fill in the blanks in the sentences below.
awfully sorrowfully completely loftily carefully differently quickly nonchalantly
(i) The report must be read ________ so that performance can be improved.
(ii) At the interview, Sameer answered our questions _________, shrugging his shoulders.
(iii) We all behave _________ when we are tired or hungry.
(iv) The teacher shook her head ________ when Ravi lied to her.
(v) I ________ forgot about it.
(vi) When I complimented Revathi on her success, she just smiled ________ and turned away.
(vii) The President of the Company is ________ busy and will not be able to meet you.
(viii) I finished my work ________ so that I could go out to play