Question

2) If 18, x, 12, 8 are in proportion, then find the value of x.​

Answer 1

★ How to do :-

Here, we are given with three numbers and a variable x. We are also said that these numbers should be in a proportion. We are asked to find the value of the variable x. So, first we will write them in the form of ratio and proportion by using thier symbols. The method used here is that, first we should find the product of extremes, the rule says that the product of extremes should be same as product of means. So, let's solve!!

$\:$

➤ Solution :-

${\tt \leadsto 18:x::12:8}$

Here,

$\tt \leadsto \boxed{\tt Means : - \: x \: and \: 12}$

$\tt \leadsto \boxed{\tt Extremes : - \: 18 \: and \: 8}$

So,

${\tt \leadsto (18 \times 8) = (x \times 12)}$

${\tt \leadsto 144 = (x \times 12)}$

${\tt \leadsto x = \dfrac{144}{12}}$

${\tt \leadsto \orange{\underline{\boxed{\tt x = 12}}}}$

$\:$

Verification :-

${\tt \leadsto 18:12::12:8}$

Write them as fractional form.

${\tt \leadsto \dfrac{18}{12} = \dfrac{12}{8}}$

Multiply the numbers as cross multiplication method.

${\tt \leadsto 18 \times 8 = 12 \times 12}$

${\tt \leadsto 144 = 144}$

${\leadsto \text{LHS = RHS}}$

$\:$

Hence verified !!