Hey there!:
Amount of purified acid phosphatase added to tube A = 5 ug ( micrograms )
Amount of acid phosphatase present in 400 ug of wheat germ extract in tube B :
1 / 100 = 5x / 400 =
100 x = ( 0.5 ) ( 400 ) =
x = (0.5 ) ( 400 ) = 100
x = 200 / 100
x = 2 ug
The amount of acid phosphatase present in 400 ug of the wheat germ in tube B is 2 ug
Hope that helps!