An asynchronous transmission scheme uses 8 data bits, a start bit, an
even parity bit, and a stop element of length 2 bits. What percentage
of clock inaccuracy can be tolerated at the receiver with respect to
the framing error?

Assumption:  
(a) The bit samples are taken at the middle of the clock period. 
(b) At the beginning of the start bit the clock and the incoming bits
are    in phrase.

Explaination required in detail.