Two identical resistors, each of 10 ohm, are connected in parallel. This combination, in turn, is connected to a third resistor of 10 ohm. The equivalent resistance of the combination is ___.
A hand made paper workshop can hire 8 craftsmen by paying them Rs 400 per person per day. The 9th craftsman demands Rs 450 per day. If this craftsman is hired then all other craftsmen must be paid Rs 450. The marginal resource (labour) cost of the 9th craftsman is