JAMB Mathematics 2018 Paper

Concept:This problem involves both selection and arrangement.First choose the letters, then arrange them into distinct words.Explanation:Step 1: Choose 3 consonants from 7.Number of ways $= ^7C_3 = 35$.Step 2: Choose 2 vowels from 4.Number of ways $= ^4C_2 = 6$.Step 3: The selected 5 letters can be arranged to form different words.Number of arrangements $= 5! = 120$.Total number of words $= 35 \times 6 \times 120$.$= 210 \times 120 = 25200$.Answer:$25200$ words can be formed.Correct option: D.