Question

Raj is twice as old as rani five years ago his age was three times rani age find rani age
a) 10 years
b) 5 years
c) 6 years
d) 8 years​

Answer 1

Answer:

(a) 10 years

Step-by-step explanation:

Let Raj's age be x years

Let Rani's age be y years

ATQ,

$x = 2y$

and

$x - 5 = 3(y - 5) \\ x - 5 = 3y - 15 \\ x - 3y = - 15 + 5 \\ x - 3y = - 10$

Substituting x = 2y

$(2y) - 3y = - 10 \\ - y = - 10 \\ y = 10$

Substituting y in x = 2y

$x = 2 \times (10) \\ x = 20$

Hence Raj's age is 20 years and Rani's age is 10 years

Thus option A is correct

Answer 2

Answer:

let age of Raj be   ′  x  ′  and age of Rani be ′  y  ′  then according to question

x = 2y                          ---------------------(1)

and five years ago  

x − 5 = 3 (y−5)

x − 5 = 3y − 15

x − 3y + 10 = 0                 ------------------------(2)

using eq (1) we get,

2y − 3y + 10 = 0

y = 10  and x = 20

hence Rani's age is 10 yrs. Correct option is ' a '