Question

The sum of two numbers is 5/2 of the first number. the second number is what percent of the first?

Answer 1

Let the 1st number be x and 2nd number be y

According to the given condition

x+y = 2.5x

y = 1.5x ... For the percentage just multiply the RHS by 100

So y = 150% of x

Answer 2

Let the numbers be x and y

$x + y = \frac{5x}{2} \\ y = \frac{5x}{2 } - x \\ y = \frac{3x}{2} \\ \\ have \: to \: find \: percentage \:o f \: y \: in \: x \\ so \\ \\ = \frac{y}{x} \times 100 \\ = \frac{ \frac{3x}{2} }{x} \times 100 \\ \frac{3}{2} \times 100 \\ 75\%$