Simple Math ques !

[Anjali]

2. A single letter is selected at random from the word Probability . The probability that it is not a vowel , is
3/11
2/11
4/11
0


3. At compound interest rate if a certain sum of money doubles in n years then the amount will four fold in
2n^2 years
n^2
4n
2n

[Homer Simpson]

1(b), 2 - nothing seems to be matching  , 3(d)

[Anjali]

For 1st , shouldn't it be , F(1)-F(1/2)
Even my ans is not matching with with 2nd ques options - shouldn't it be 7/11 ?
For d even m getting the same as yours

[SoniaKapoor]

HOW to approach the 3rd one?

[Akshay Jain]

Le the amt of money be A
given dat 2*A=A*(1+r)^n
now 4*A= 2*(2*A)
so 4*A= 2*(A*(1+r)^n)
again substitute value of 2*A in above eqn
(A*(1+r)^n)*(1+r)^n
=(A*(1+r)^2n)
so ans is 2n