# Probability JSS 2 Third Term Mathematics Scheme of Work with Lesson Notes

Solution:

(a) Probability of picking an odd number:

– Count the total number of odd numbers between 15 and 30: 15, 17, 19, 21, 23, 25, 27, 29 (8 numbers)

– The total number of numbers between 15 and 30 is 30 – 15 + 1 = 16 numbers

– Probability = Number of favorable outcomes / Total number of possible outcomes

– Probability of picking an odd number = 8 / 16 = 1/2 = 0.5

(b) Probability of picking an even number:

– Count the total number of even numbers between 15 and 30: 16, 18, 20, 22, 24, 26, 28, 30 (8 numbers)

– Probability of picking an even number = 8 / 16 = 1/2 = 0.5

(c) Probability of picking a number divisible by 3:

– Count the total number of numbers divisible by 3 between 15 and 30: 15, 18, 21, 24, 27, 30 (6 numbers)

– Probability of picking a number divisible by 3 = 6 / 16 = 3/8 = 0.375

(d) Probability of picking a prime factor of 30:

– Prime factors of 30 are 2, 3, and 5.

– Count the total number of prime factors of 30 which are 2,3 and 5 (3 numbers)

– Probability of picking a prime factor of 30 = 3 / 16

(e) Probability of picking a number less than or equal to 24:

– Count the total number of numbers between 15 and 30 that are less than or equal to 24: 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 (10 numbers)

– Probability of picking a number ≤ 24 = 10 / 16 = 5/8 = 0.625

Note: The probabilities are expressed as fractions and decimals for clarity.