Question

The shear strength of common building stones in terms of their compressive strength typically varies from

• A. 10 to 20
• B. \( \frac{1}{5} \) to \( \frac{1}{10} \)
• C. \( \frac{1}{10} \) to \( \frac{1}{20} \)
• D. 5 to 10

Hint:

Building stones are very strong in compression but much weaker in shear. The shear strength is therefore only a small fraction of the compressive strength.

Answer 1

The Correct Option is C

Concept:
Building stones are very strong in compression but much weaker in shear. The shear strength is therefore only a small fraction of the compressive strength.

Step 1:
Since shear strength is much less than compressive strength, the ratio must be a small fraction, not a number greater than one. This rules out options like 10 to 20 and 5 to 10.

Step 2:
For common building stones, the shear strength is generally about one-tenth to one-twentieth of the compressive strength, i.e. \( \frac{1}{10} \) to \( \frac{1}{20} \).

Answer: Option (3) — \( \frac{1}{10} \) to \( \frac{1}{20} \).