Given, 5/2x = 10

=> 5/2x = 10/1

Now, apply cross multiplication, we get

     5 * 1 = 2x * 10

=> 5 = 20x

=> 20x = 5

=> x = 5/20

=> x = 1/4        {5 and 20 are divided by 5}

So, the value of x is 1/4