Question

the ratio of ages A and B is 3:4 after 5 years there ages will 4:5 what is present age of B? ​

Answer 1

Answer: 4$\sqrt{5}$

Step-by-step explanation:

Let 3x and 4x be the ages A and B.

3x:4x=4(x+5):5(x+5)

3x:4x=4x+20:5x+25

3x(5x+25)=4x(4x+20)

15x²+75=16x²+80

16x²-15x²=80-75

x²=5

x=$\sqrt{5}$

∴The ages of b is 4$\sqrt{5}$.

Answer 2

Answer:

20

Step-by-step explanation:

present age of A=3x

present age of B=4x

after five years the age of A=3x+5

after five years the agw of B=4x+5

the ratio between A and B

=3x+5/4x+5

but given=4:5

3x+5/4x+5=4/5

(3x+5)5=(4x+5)4

15x+25=16x+20

25-20=16x-15x

5=x

present age of B=4x(x=5)

4(5)=20