90 single use contacts come in 1 box and will last Pete 45 days.  Each box is $100.00 and currently 10% off.  If he buys 2 boxes of contact, how much will each pair of contacts cost?
Each box of contacts is $100.00 with 10% off so that's 100*.10 = $<<100*.10=10.00>>10.00 off
So the box was $100.00 and he has $10.00 off so each box will cost 100-10 = $<<100-10=90.00>>90.00
He buys 2 boxes and each box costs $90.00 so that's 2*90= $<<2*90=180.00>>180.00
1 box of contacts has 90 contacts and he buys 2 boxes so that's 90*2 = <<90*2=180>>180 contacts
He needs 1 contact for each eye and he has 180 contacts so that's 180/2 = <<180/2=90>>90 pairs of contacts
He spent $180.00 to have 90 pairs of contacts so each pair of contacts costs 180/90 = $<<180/90=2.00>>2.00 a pair
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