Question

In 20 years Mark will be three times as old as he was 10 years ago how old is he

Answer 1

Age of Mark is 25 years.

Explanation:

Let the current age of Mark = x years

After 20 years, age of Mark=(x+20) years

10 years ago,age of Mark was (x-10) years.

In 20 years Mark will be three times as old as he was 10 years ago.

=>
`\[(x+20) = 3*(x-10)\]`

=>
`\[(x+20) = 3x-30\]`

=>
`\[(3x-x) = 30+20\]`

=>
`\[(2x) = 50\]`

=>
`\[x = (50)/(2)\]`

=>
`\[x = 25\]`