Screen analysis notation: interpret the size class denoted as “+5 mm / −10 mm”. Which statement correctly describes the particles in this fraction?

Introduction / Context:
Screen analysis classifies particulate solids by their ability to pass or be retained on standard apertures. Understanding shorthand notations like “+a / −b” is essential when reading sieve analyses, designing screen decks, or comparing product specs.

Given Data / Assumptions:

• “+a” means the particles are larger than a (retained on a sieve of aperture a).
• “−b” means the particles are smaller than b (pass through b).
• Here, a = 5 mm and b = 10 mm.

Concept / Approach:
Particles labeled “+5 mm / −10 mm” are those that pass a 10 mm sieve but are retained on a 5 mm sieve. This describes the size interval between 5 and 10 mm inclusive of screening conventions (with a practical tolerance due to near-mesh particles and shape effects).

Step-by-Step Solution:
Interpret “+5”: retained on 5 mm, so size ≥ 5 mm (by screening convention).Interpret “−10”: pass 10 mm, so size ≤ 10 mm.Combine: 5–10 mm class, i.e., pass 10 mm and retain on 5 mm.

Verification / Alternative check:
Check typical screen analysis tables: fractions are commonly labeled with an upper “minus” (passing) and lower “plus” (retained) bound to define the interval.

Why Other Options Are Wrong:
“Pass 5 mm and retain on 10 mm” is impossible because a particle cannot be larger than 10 mm and simultaneously pass it.“Pass both” or “neither” do not define a standard size interval.

Common Pitfalls:
Reversing the “+” and “−” meanings; always remember “+” ties to retention (coarser than) and “−” to passing (finer than) the stated size.

Final Answer:
Passing through 10 mm screen and retained on 5 mm screen