Important for :

1

E

Let the present age of Navya = 5x, Reet = 6x

After 8 years,

5x + 8 : 6x + 8 = 7 : 8

(5x + 8) 8 : (6x + 8) 7

40x + 64 = 42x + 56

64 – 56 = 42x – 40x

8 = 2x

x = 4

Present age of Navya = 20, Reet = 24

After 10 years the total of their ages = 20 + 10 + 24 + 10 = 64

Hence, option E is correct.

After 8 years,

5x + 8 : 6x + 8 = 7 : 8

(5x + 8) 8 : (6x + 8) 7

40x + 64 = 42x + 56

64 – 56 = 42x – 40x

8 = 2x

x = 4

Present age of Navya = 20, Reet = 24

After 10 years the total of their ages = 20 + 10 + 24 + 10 = 64

Hence, option E is correct.

2

E

Since Monika and Neha are twins so their ages be same. Let their ages be x and and age of Bharti be y, then,

x + x = y**...(i)**

x + x = y

and | (x – 3) | = | 5 |

(y – 3) | 11 |

⇒ 11x – 33 = 5y – 15

⇒ 11x – 5y = 18

Now, from equation (i) putting y in terms of x, we get

11x – 10x = 18

⇒ x = 18

So, the age of Bharti 7 years hence will be 18 + 18 + 7 = 43 years.

Hence, option E is correct.

3

D

Total age of 20 employees = 20 × 26 = 520

Let the average age of 5 new employees be x.

Therefore, the total age of the new employees = 5x

Hence, the total age of 20 employees = 360 + 5x

The average age of the new employees = 32

Hence, option D is correct.

Total increment in Group's age (15 + 5) × 2 = 40 years

Now, avg age of new employees = 24 + | 40 | = 32 years |

5 |

4

B

Let the present age of John be x and that of his son be yForming equations

x – 5 = 5(y – 5)

x + 5 = 3(y + 5)

After soving we get

x = 55 and y = 15

After how many years, he will be twice as old as son

55 + x = 2 (15 + x)

x = 25 years

The answer can be found by trying options

= | (55 + 25) | = 2 |

(15 + 25) |

Hence, option B is correct.

5

D

Let age of Rajan be x and that of his son be y

So as per the question:

(x – 2) : (y – 2) = 4 : 1 or 4 (y – 2)= x – 2 (this is the first equation)

(x + 5) : (y + 5) = 5/2 or 5(y + 5)= 2(x + 5) (this is the second equation)

Solving both of them we get x = 30 and y = 9

So present age of the son is 9 years

Hence, option D is correct.

Hence, option D is correct.