Among employees at Daly Developers Ltd, 80% use R, 60% use Python, and 50% use both

Statistics Nov 18, 2020

Among employees at Daly Developers Ltd, 80% use R, 60% use Python, and 50% use both. What proportion of programmers use either R or Python? A computer program is subjected to two independent tests. These tests will discover an error with probabilities 0.8 and 0.7 respectively. Suppose a program contains an error, what is the probability that it will discovered?