What will be obtained if 8 is subtracted from the H.C.F. of 168, 189 and 231 ?
2024
What will be obtained if 8 is subtracted from the H.C.F. of 168, 189 and 231 ?
- A.
15
- B.
10
- C.
21
- D.
None of these
Attempted by 4 students.
Show answer & explanation
Correct answer: D
To find the final result, we need to first calculate the Highest Common Factor (H.C.F.) of 168, 189, and 231, and then subtract 8 from that value.
Step-by-Step Calculation
1. Find the H.C.F. of 168, 189, and 231: We can find the H.C.F. by prime factorization or by finding the differences between the numbers.
Prime Factorization:
168 = 2 × 84 = 2² × 42 = 2³ × 21 = 2³ × 3 × 7
189 = 3 × 63 = 3² × 21 = 3³ × 7
231 = 3 × 77 = 3 × 7 × 11
Identify Common Factors:
The only prime factor common to all three numbers (168, 189, and 231) is 3 and 7.
H.C.F. = 3 × 7 = 21.
2. Subtract 8 from the H.C.F.:
H.C.F. = 21
Result = 21 - 8 = 13.