Сумма первого и второго числа 20, первое число это 25% второго какое это число ?

Let's denote the first number as x and the second number as y.

According to the given information, we have the following two equations:

1. x + y = 20 (sum of the two numbers is 20)
2. x = 0.25y (the first number is 25% of the second number)

Substitute the second equation into the first equation: 0.25y + y = 20 1.25y = 20 y = 20 / 1.25 y = 16

Now that we have found the value of the second number (y), we can substitute it back into the second equation to find the value of the first number (x): x = 0.25 * 16 x = 4

Therefore, the first number is 4 and the second number is 16.