Question

LEVEL-1
1. A father is three times as old as his son. After twelve years, his age will be twice as the
of his son then. Find their present ages
2. Ten years later. A will be twice as old as Band five years ago, A was three times as old as
B. What are the present ages of A and B?
3. Five vears ago Nuri was thrice as old as Sonu. Ten years later, Nuri will be twice as old
as Sonu. How old are Nuri and Sonu?
INCERT)
4. Six years hencea man's age will be three times the age of his son and three years ago he
was nine times as old as his son. Find their present ages.
5. Ten years ago, a father was twelve times as old as his son and ten years hence, he will be
twice as old as his son will be then. Find their present ages.
​

Answer 1

Answer:

(1)x=36,y=12

(2)a=50,b=20

Step-by-step explanation:

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1. Let father's age be x

his son's age be y

The given equations are..

=> x=3y

=>x-3y=0 -----(1)

=>x+12=2(y+12)

=>x+12=2y+24

=>x=2y+24-12

=> x=2y+12

=>x-2y=12 ------(2)

subtracting equation (1) from (2)

x-2y=12

- x-3y=0

___________________

y=12

=>y=12

putting the value of y in equation (1)

=>x-3y=0

=>x-3(12)=0

=>x-36=0

=>x=0+36

=>x=36

Therefore, father's age is 36 and his son's age is 12.

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2. The given equations are...

=>a+10=2(b+10)

=>a+10=2b+20

=>a=2b+20-10

=>a=2b+10

=>a-2b=10 -------(1)

=>a-5=3(b-5)

=>a-5=3b-15

=>a=3b-15+5

=>a=3b-10

=>a-3b=-10 -------(2)

Subtracting equation (1) from (2)

a-3b=-10

- a-2b=10

____________

-b=-20

=>b=20

putting the value of b in equation (1)

=>a-2b=10

=>a-2(20)=10

=>a-40=10

=>a=10+40

=>a=50

Therefore,the present age of a is 50 and b is 20.

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