There are 4 candidates for a Chemistry scholarship, 5 for a Mathematical scholarship, and 6 for a Biology scholarship. In how many ways can these scholarships be awarded?
There are 4 candidates for a Chemistry scholarship, 5 for a Mathematical scholarship, and 6 for a Biology scholarship. In how many ways can these scholarships be awarded? Correct Answer 120
Given:
Number of candidates in chemistry = 4
Number of candidates in mathematics = 5
Number of candidates in biology = 6
Concept: /Formula:
Factorial Notation:
Let n be a positive integer. Then, factorial n, denoted n! is defined as :
n! = n × (n - 1) × (n - 2) ... 3 × 2 × 1
The different arrangements of a given number of things by taking some or all at a time, are called permutations.
Number of Permutations:
Number of all permutations of n things, taken r at a time, is given by :
nPr = n!/(n - r)!
Combinations:
Each of the different groups or selections which can be formed by taking some or all of a number of objects is called a combination.
Number of Combinations:
The number of all combinations of n things, taken r at a time is :
nCr = n! /(r!) (n - r)!
Calculation:
Scholarships are one per subject
Number of candidates in chemistry = 4
Number of candidates in mathematics = 5
Number of candidates in biology = 6
∴ Required number of ways = 4C1 × 5C1 × 6C1 = 4 × 5 × 6 = 120