Respuesta :

faizu
let the unknown number be a ...

87 1/2 % * a = 35
=> 175/2/100 * a = 35
=> 175/2 * 1/100 * a =35
=> 175/200 a = 35
=> 0.875 a=35
=> a = 35 / 0.875
=> a  = 40
so 87 1/2% of 40 is 35 ..

Hope it helps !!!