Suppose you roll a special 29-sided die. What is the probability that the number rolled is a "1" OR a "2"?
what I did was
( 1/29 + 1/29)- 1/841
however , that didn't work , so can someone help me with this exercise ?
Assuming things like all sides are equally likely, the sides are numbered 1 through to 29 etc. etc., then the probability of rolling a 1 or a 2 in a single roll of the die is obviously 2/29.
(From your blind application of a well known formula it appears that you think that in a single roll it's possible for both a 1 and a 2 to appear ....)