Given:
We are given 4 cards numbered 6,7,8 and 9.
To find:
The probability of picking a number less than 8 and picking a number greater than 7.
Step by step solution:
1) Picking a number less than 8:
= Two cards are less than 8, out of 4 cards.
= 2/4
= 1/2
2) Picking a number more than 7:
= Two cards are more than 7, out of 4 cards.
= 2/4
= 1/2
Getting the combined probability of both cases:
P(X) = P(A)P(B)
P(X) = 1/2 × 1/2
P(X) = 1/4
Upon converting the probability into the percentage form:
P(X) = 1/4 comes out to be 25%