Solution of problem N4972 probability theory

Solution of problem N4972 probability theory

4972. There are 26 parts in the box, among which 21 are standard. The buyer is sent 2 parts. Find the probability that:
1) all non-standard parts were left in the box;
2) among the sent parts, one part is standard and the other is non-standard;
3) at least one of the two sent parts will be standard.

Additional information:

Detailed solution. Decorated in Microsoft Word 2003 (Quest decided to use the formula editor)

Discount for regular customers! If the total of your purchases from the seller Massimo86 exceeds:

• $30 discount 10%
• $20 discount 7%
• $18 discount 6%
• $15 discount 5%
• $12 discount 4%
• $9 discount 3%
• $6 discount 2%
• $3 discount 1%