Question

what is the average age of A and B ?
The ratio between one-fifth of A's age one-fourth
of B's age is 1;2
The product
оf their age is 20 times
B's age
​

Answer 1

Answer:

Let the present age of A be 'x ' years & B be y years.

x = y-10

x-y = -10

Four years hence A= (x +10) years

Four years hence B = ( y+ 10) years

x+10/y+10 = 3/5

5(x+10) = 3(y+10)

5x+50 = 3y + 30

5x-3y = 30–50

5x-3y = -20 ————(2)

Multiplying first equation by 3

3x-3y = -30 ————(3)

Subtraction (2) - (3)

2x= 10

x = 5

Substituting x= 5 in equation (1)

5= y-10

y= 15

Verification

x+10/y+15

= 5+10/15+10

=15/25

= 3/5

Present age of A is 5 years & B is 15 years.

Step-by-step explanation:

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