Exams

Let the present age of Ravali = x

=> Swarna's present age = x - 9

From the given data,

x + 7 = 2(x - 9 + 7)

=> x = 11 yrs

Required Ravali's age after 4 years = 11 + 4 = 15 yrs.

Cp1 = p2 - p1 ,
Cp2 = p3 - p2
..
..
..
Cp23 = p24 - p23
Sum of series = (p2-p1) + (p3-p2) + .....(p23-p22) + (p24-p23)
All terms get cancelled, except p1 = 2 and p24 = 89
So Sum = -p1 + p24
Sum of series = -2 + 89 = 87

State-run NTPC said the company has forayed into electric vehicle charging business and has set up first such charging stations at its offices in Delhi and Noida. Adding that the move will push demand for electric vehicles, an official said, "The main objective in setting up the charging points is to be part of promoting clean energy transportation."

Surface roughness on a drawing is represented by the triangle.

Labor unions are associations of workers who pursue common objectives. Workers use this platform to bargain collectively on behalf of the majority of workers.

Two series alternate here, with every third number following a different pattern.
In the main series, 4 is added to each number to arrive the next.
In alternate series, 5 is subtracted from each number t arrive the next number.
Here in the main series 
3 + 4 = 7
7 + 4 = 11
11 + 4 = 15
15 + 4 = 19

In alternate series 
24 - 5 = 19
19 - 5 = 14...

When modifiers are misplaced or put in the wrong place, things can get quite confusing. A modifier adds detail or limits or changes the meaning of another word or phrase. 

Here Option A) "Covered in fluffiness, the couple played with the kitten" is the ony sentence contains a misplaced modifier. In the sentence, it gives the meaning that the couple are fluffy not the kitten.