Posted by matt on Thursday, May 13, 2010 at 10:47pm.
1/30 = .033 envelopes/sec
1/40 = .025 envelopes/sec
so
.033+.025 = .058 envelopes /sec together
1/.058 = 17.2 seconds/envelope
140 envelopes * 17.2 seconds/envelope = 2413 seconds or 40 minutes
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