Question

15 is the solution to which of the below equations?

• A. $\frac{x+4}{4}+\frac{x-5}{3}=11$
• B. $\frac{m+4}{2}+\frac{m+10}{9}=8$
• C. $\frac{x+24}{5}=4+\frac{x}{4}$
• D. $\frac{y+15}{10}+\frac{y-5}{5}=5$

Answer 1

The correct option is D $\frac{y+15}{10}+\frac{y-5}{5}=5$

Whenever, you get question like this, the best approach is to plug and check.

Let us substitute 15 in each equation in place of variable

Option A) $\frac{15+4}{4}+\frac{15-5}{3}$

$\frac{19}{4}+\frac{10}{3}$ this will clearly give a fractional value,and not equal to RHS (11).

Therefore, option A is eliminated

Option B) $\frac{15+4}{2}+\frac{15+10}{9}$

$\frac{19}{2}+\frac{25}{9}$ by same logic; this option is also eliminated.

Option C) $\frac{x+24}{5}=4+\frac{x}{4}$

$\frac{15+24}{5}$ = $\frac{39}{5}$ = LHS

$\frac{16+15}{4}$ = $\frac{31}{4}$ = RHS

$\frac{39}{5}\ne \frac{31}{4}$

As, options A, B and C are eliminated clearly the answer is option D.

A quick check!

Option D) $\frac{y+15}{10}+\frac{y-5}{5}=5$

Substituting y = 15, we get

$\frac{15+15}{10}+\frac{15-5}{5}=5$

$\frac{30}{10}+\frac{10}{5}=5$

$3+2=5$

L.H.S = R.H.S

Hence, option D is correct answer