Question

12. Fifteen years from now Ravi's age will be four times his present age. What is Ravi's present age ?​

Answer 1

Answer:

let Ravi's age be x.

according to the question.

x + 15 = 4x

x-4x= 15

-3x = 15

x = 15/3.

x= 5=answer.

so Ravi's present age is 5 years.

Answer 2

$\bf \: \underline{Given} :$ ↴

$\sf Fifteen \: years\: from\: now \: Ravi's \: age \: will \: be \: four\: times \: his\: present\: age.$

$\bf \underline{To \: find} :$ ↴

$\sf We \: have \: to \: find \: Ravi's\: present \: age.$

$\bf \: \underline{ \underline{So, \: Let's \: Start}}$

$\sf Let \: us \: assume \: that\: the \: present \: age \: of \: Ravi \: is \: x.$

$\bf \: So,$

$\sf The \: equation \:will \:be\: x\: +\: 15 = \:4x$

$\sf \implies \: x + 15 = 4x$

$\sf \: On \: transposing \: we \: get,$

$\sf \implies \: x - 4x = -15$

$\sf \implies \: -3x = -15$

$\sf \implies \: 3x = 15$

$\sf \implies \: x = \dfrac{1}{3}$

$\sf \implies \: x = 5$

$\boxed{\pink{ \sf So, \: Ravi's \:Present \:age\: is \:5.}}$

________________________________

$\bf \underline{Let's \: verify \: our \: answer} :$ ↴

If you're not sure with our answer, then there is one way to check it. Substitute the value of 'x' in the equation we have formed. If the answer is correct, we will get LHS to be equal to RHS.

$\sf \implies \: x + 15 = 4x$

$\sf Here, \: we \:have \:write\: 5\: instead\: of \:x.$

$\sf \implies \: 5 + 15 = 4\times 5$

$\sf \implies \: 20 = 20$

$\sf \implies \: LHS = RHS$

$\sf \underline{Hence\: our \: answer\: is \: correct}..$