we know that
The probability of losing the national treasure from A to Q is 0.02
so
The probability that not losing the national treasure from A to Q is 1-0.02=0.98
The probability that not losing the national treasure from Q to U is 1-0.04=0.96
The probability that not losing the national treasure from U to W is 1-0.05=0.95
The probability that not losing the national treasure from W to Z is 1-0.03=0.97
therefore
The probability that not losing the national treasure from A to Z is equal to
P=0.98*0.96*0.95*0.97
P=0.8669