Question

Five years ago, Anu was thrice as old as Sonu. After ten years, Anu will be

twice as old as Sonu. How old are Anu and Sonu?​

Answer 1

Step-by-step explanation:

$five \: years \: ago \: \\ let \: the \: age \: of \: anu \: be \: 3x \: and \: sonu \: be \: x \\ after \: 10 \: years \\ anu \: age \: = 3x + 10 \\ sonu \: age \: = x + 10 \\ according \: to \: question \\ 3x + 10 = 2(x + 10) \\ = 3x + 10 = 2x + 20 \\ = 3x - 2x = 20 - 10 \\ = x = 10 \\ anu \: age \: = 3x \\ = 3 \times 10 \\ = 30 \\ sonu \: age \: = x \\ = 10$

Answer 2

Answer:

Anu's age is 50 and Sonu's age is 20

Step-by-step explanation:

Let the present age of

Anu be = x

Sonu be = y

Step 1 -

x-5 = 3(y-5)  [substracted five as five years ago]

x-5 = 3y-15  [opening bracket]

x   = 3y-15+5  [transposing 5 to RHS and changing - to +]

x   = 3y-10  [value of x]

Step 2 -

      x+10 = 2(y+10)  [added 10 as after ten years]

      x+10 = 2y+20  [opening bracket]

3y-10+10 = 2y+20 [adding value of x as per step 1]

    3y-2y = 20  [transposing 2y to LHS and changing + to -]

           y = 20 [value of y and age of Sonu]

Step 3 -

x = (3×20)-10 [using the value of x and y]

x = 60-10

x = 50  [Age of Anu]

Hence, Anu is 50 years old and Sonu is 20 years old.