MATHEMATICS

JAMB 2001 - Question 47

Mathematics 2001 JAMB Past Questions - Question 47: find the number of ways of selecting 8 subjects from 12 subjects for an examination

find the number of ways of selecting 8 subjects from 12 subjects for an examination
A:
B:
C:
D:
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Correct Answer

C

Explanation

The number of ways of selecting 8 subjects from 12 subjects for an examination can be calculated using the combination formula.The formula for combinations is given by:C(n, r) = n! / (r!(n-r)!)Where n is the total number of subjects and r is the number of subjects to be selected.In this case, we have n = 12 and r = 8.Plugging in the values into the formula, we get:C(12, 8) = 12! / (8!(12-8)!)Simplifying further:C(12, 8) = 12! / (8! * 4!)Calculating the factorials:12! = 12 * 11 * 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 18! = 8 * 7 * 6 * 5 * 4 * 3 * 2 * 14! = 4 * 3 * 2 * 1Substituting the values into the formula:C(12, 8) = (12 * 11 * 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1) / ((8 * 7 * 6 * 5 * 4 * 3 * 2 * 1) * (4 * 3 * 2 * 1))Simplifying the expression:C(12, 8) = (12 * 11 * 10 * 9) / (8 * 7 * 6 * 5 * 4 * 3 * 2 * 1)Cancelling out common factors:C(12, 8) = (12 * 11 * 10 * 9) / (8 * 7 * 6 * 5 * 4 * 3 * 2 * 1)C(12, 8) = 495Therefore, there are 495 ways of selecting 8 subjects from 12 subjects for the examination.