An electronic store receives 20 calculators, 7 are defective. Four of the calculators are sent to a high. What's the selections of no defective calculators

4845 selection

Step-by-step explanation:

If the only distinction between calculators is the defects then there are 4 possible selections, namely

0, 1, 2, 3 defective calculators along with good ones for the balance.

If the calculators bear serial numbers, i.e. they are considered distinct, then there are (20,4)=20!/(4!16!)= 4845 selections.

∞ this is your sign