Question

present age of 30 years and 35 respectively after how many years their ages will be 7: 8​

Answer 1

Answer:

after 5 years ago...

their age in the ratio of 7:8

Step-by-step explanation:

In present their age is 30 after 5 years her age is 35

second age is 35 after 5 years her age is 40

and 35 and 40 is in the ratio of 7:8........

I hope it will help

Answer 2

Answer:

After 5 years, ratio of age of A and B will be 7 : 8

Step-by-step explanation:

Let present age of A is 30 years

Let present age of B is 35 years

Let us assume that after $x$ years, ratio of age of A and B will be 7 : 8

Age of A after $x$ years $= (\,30 + x)\,$ years

Age of B after $x$ years $= (\,35 + x)\,$ years

We get

$\frac{30+x}{35+x} = \frac{7}{8}\\\\8 \times (\,30 + x)\, = 7 \times (\,35 + x)\,\\\\240 + 8x = 245 + 7x\\\\8x - 7x = 245 - 240\\\\x = 5\hspace{0.1cm}years$

Thus, after 5 years, ratio of age of A and B will be 7 : 8