A spherical metallic shell with 6 cm external radius weighs 6688 g. What is the thickness of the shell if the density of metal is 10.5 g per cm3? (Take л = 22/7)

The expression   $${15(\sqrt { 10}+\sqrt { 5})\over \sqrt { 10}+\sqrt { 20}+\sqrt { 40}-\sqrt { 5}-\sqrt { 80}     }$$ is equal to:

Select the number from among the given options that can replace the question mark (?) in the following series. 

Question figure.

A, B and C started a business. Twice the investment of A is equal to thrice the investment of B and also five times the investment of C. If the total profit after a year is 15.5 lakhs, then the share of B in the profit is (in lakhs):

In the following question below are given some statements followed by some conclusions based on those statements. Taking the given statements to be true even if they seem to be at variance from commonly known facts. Read all the conclusions and then decide which of the given conclusion logically follows the given statements.

Statements:
 I. Some F are D.
 II. No A is D.

Conclusion:
 I. Some F are A.
 II. No D is A.
 III. Some F are not A.

Select the option that is related to the third word in the same way as the second word is related to the first word. (The words must be considered as meaningful English words and must not be related to each other based on the number of letters/number of consonants/vowels in the word.)
Movie: Director :: Orchestra: ?

Select the option that represents the correct order of the given words as they would appear in an English dictionary.

1- Sennet
 2- Sennight
 3- Sennit
 4- Seniority
 5- Senna

Select the option that is related to the fifth number in the same way as the second number is related to the first number and the fourth number is related to the third number.
 7 : 25 :: 4 : 4 :: 3 : ?