Resistors produced by a certain firm are marketed as 10-ohm resistors. However, the actual resistances of the resistors may vary. It is observed that 5% of the values are below 9.5 ohms and 10% are above 10.5 ohms. If two of these resistors, randomly selected, are used in a system, find the probability that:
(a) both have actual values between 9.5 and 10.5 ohms
(b) at least one has an actual value in excess of 10.5 ohms