Let the quantity of milk and water initially = 3x and 7x respectively

Now, according to question,

(3x+6)/(7x+4) = 2/3

 9x+18 = 14x+8

X= 2

So the initial quantity of the mixture = (3x+7x) = 10x = 10x2 = 20litres

Let the rate of interest = x%

So simple interest,

(7300x3xX)/100= 10804-7300

219X = 3504

X= 16%

 √4900 + √.49 + √.000049

70+.7+.007

70.707

Hence option C

Sum of the first second and third number = 240x3 = 720

So, sum of the second and third number = 720-140 = 580

Sum of the second, third and fourth number = 210x3 = 630

So, the fourth number = 630-580 = 50

Let the income of A, B and C is 4x, 7x and 8x respectively

For C,

His total expenditure is = (10% + 30%+40%) of his total income

So he saves 20% of his income.

So, 20% of 8x = 4800

X= 3000

So the required difference between income of  A and B = 7x-4x = 3x

 = 3x3000

 = 9000

Present age of neha = (rajni’s age 4 years hence – 8) = 28-8 = 20 years

Present age of kapil = x*80/100 = 20

X= 25

Hence option D

Time in which Rohit can complete the race = 288/9 = 32 seconds

Time in which Arjun can finish the race = 288/12 = 24 seconds

So, clearly Arjun will beat Rohit by 8 seconds

Distance covered by Rohit in 8 seconds = 9x8 = 72m

So, Arjun beat Rohit by 72 meters.

Let the numbers are ‘x’ and ‘y’

Sum of first 20 multiple of x = x(1+2+3+4+…..+20) = x(20x21)/2 = 210x

Sum of first 20 multiple of y = y(1+2+3+4+…..+20) = y(20x21)/2 = 210y

Average = (210x+210y)/40

273= 2(x+y)/2

x+y =  26

Required Average = (x+y)/2 = 26/2 = 13

We know that,            

A mode of an expression is the most frequently occurring number in a set of numbers.

We have, 2,4,5,3,7,9,2,4,6,2,1,4,6,3,2,9,8,7,4,5,6,2,2,5,9

In the above set2 appears most frequently

Hence option A