Find the greatest possible length which can be used to measure exactly the…
2025
Find the greatest possible length which can be used to measure exactly the lengths 4 m 95 cm, 9 m and 16 m 65 cm.
- A.
48 cm
- B.
55 cm
- C.
45 cm
- D.
57 cm
Attempted by 29 students.
Show answer & explanation
Correct answer: C
To find the greatest possible length that can measure given lengths exactly, you need to find the Highest Common Factor (H.C.F.) of the measurements.
Step-by-Step Calculation
1. Convert all measurements to the same unit (centimeters):
4 m 95 cm = 400 cm + 95 cm = 495 cm
9 m = 900 cm
16 m 65 cm = 1600 cm + 65 cm = 1665 cm
2. Find the H.C.F. of 495, 900, and 1665:
Prime factorization:
495 = 5 * 9 * 11 = 3^2 * 5 * 11
900 = 9 * 100 = 3^2 * 2^2 * 5^2
1665 = 5 * 333 = 5 * 9 * 37 = 3^2 * 5 * 37
The H.C.F. is determined by the lowest power of common prime factors:
Common factors: 3^2 and 5^1
H.C.F. = 9 * 5 = 45 cm.