A prime number is a number greater than one that can only be divided by one and itself. The possible prime sums we can reach are three, five, seven, and eleven.
Pairs that sum to three: (1, 2) — 1 pair
Pairs that sum to five: (1, 4) and (2, 3) — 2 pairs
Pairs that sum to seven: (1, 6), (2, 5), and (3, 4) — 3 pairs
Pairs that sum to eleven: (5, 6) — 1 pair
Adding these together gives one plus two plus three plus one, which equals seven favorable pairs.
Step 3: Calculate the probability
Favorable outcomes: 7
Total possible pairs: 15
The probability of choosing two numbers whose sum is prime is 7 out of 15.
Correct Answer:
C) 7/15
Answer verified by Quintessence Classes faculty — Karan Nagar, Srinagar.
