N-01-01-004-vr-007 Casio fx-82NL
It = I1 + I2 + I3
I3 = It - ( I1 + I2 )
I3 = 1 - (10mA + 90mA)
I3 = 1000 mA - 100 mA = 900 mA
┘
1 - ( 10 -3 + 90 -3 ) 0.9 A = 900 mA