How many ways can 5 different letters be arranged if 2 letters must always be to

Practice Questions

Q1
How many ways can 5 different letters be arranged if 2 letters must always be together?
  1. 60
  2. 120
  3. 240
  4. 720

Questions & Step-by-Step Solutions

How many ways can 5 different letters be arranged if 2 letters must always be together?
  • Step 1: Identify the 5 different letters. Let's call them A, B, C, D, and E.
  • Step 2: Choose the 2 letters that must always be together. For example, let's say we choose A and B.
  • Step 3: Treat the 2 letters (A and B) as one single unit or block. Now, instead of 5 letters, we have 4 units to arrange: (AB), C, D, and E.
  • Step 4: Calculate the number of ways to arrange these 4 units. The formula for arranging n units is n!. Here, n = 4, so we calculate 4! (which is 4 x 3 x 2 x 1 = 24).
  • Step 5: Since A and B can be arranged within their block in 2 different ways (AB or BA), we need to multiply the arrangements of the 4 units by the arrangements of A and B. This gives us 4! * 2! = 24 * 2 = 48.
  • Step 6: Therefore, the total number of ways to arrange the 5 letters with A and B always together is 48.
  • Permutations – The arrangement of objects in a specific order, considering the total number of objects and any constraints.
  • Grouping – Treating a set of items as a single unit to simplify the arrangement process.
Soulshift Feedback ×

On a scale of 0–10, how likely are you to recommend The Soulshift Academy?

Not likely Very likely