Question

The sum of two numbers is $550$. If $3.5$ of the number is equal to $7.5$ of the other, find the numbers.

• A. $325$ and $225$
• B. $375$ and $175$
• C. $200$ and $350$
• D. None of the above.

Answer 1

Answer: (B)

$375$ and $175$

Let the first number be $x$.
Then, the other number will be $550-x$.
By the given condition, we have

$3.5\times x=7.5\times (550-x)$

$⟹\frac{35}{10}\times x=\frac{75}{10}(550-x)$

$⟹35x=(75\times 550)-75x$

$⟶35x+75x=41250$

$⟹110x=41250$

$⟹x=\frac{41250}{110}$

$⟹x=375$

The first number $=550-375$= $175$

So, option B is correct.