I'm having a but of a rough time with this question.
At first I thought like this: MPV = (budget price- actual price) * actual quantity. 400 = (1-actual price)*actual quantity
400 = actual quantity - actual price * actual quantity
then I thought this : actual material = flexible material
actual material price * actual material quantity = actual material quantity * budget price * usage ratio
actual material price * actual material quantity = actual material quantity *1*2
actual material price * actual material quantity = 2*actual material quantity
400 = actual quantity - 2*actual material quantity
400 = -actual quantity.
But it cannot be this, therefore I'm a bit lost on where i went wrong, or what I should do it