OC Thinking Skills Practice Test 17 — 2027 NSW Opportunity Class Exam

Step 1: Understand the problem.

Angelo is painting the entire outside surface of the solid — including the bottom faces that sit on the floor. Every exposed face of every cube gets painted.

Step 2: Count all exposed faces for each cube position.

The solid is a staircase arrangement. Work through each cube position systematically and count how many of its 6 faces are exposed (not touching another cube or hidden inside the solid).

Going through all the cube positions one by one and adding up the exposed faces:

5 + 4 + 3 + 4 + 4 + 5 + 4 + 4 + 5 + 3 + 2 + 3 + 2 + 3 + 2 = 53

Step 3: Check your work.

There are 15 cubes in total. If each cube were completely separate, there would be 6 × 15 = 90 faces. Cubes that share a face with a neighbour lose 2 faces from the exposed count. With 53 exposed faces, this means 90 − 53 = 37 faces are hidden inside the solid, which is consistent with the number of adjacent cube-pairs.

The total number of faces painted yellow is 53.

Step 1 — Apply the first two clues.

• Bo is somewhere to the LEFT of Cleo
• Drew is somewhere to the RIGHT of Cleo

These two clues together fix the relative order of Bo, Cleo, and Drew:

Bo  ...  Cleo  ...  Drew
(Bo always left)    (Drew always right)

Step 2 — Place Ava.

Ava is NOT on either end (not position 1 or position 4). She must go into position 2 or 3.

The only valid arrangements are:

Valid arrangement 1:   Bo | Ava | Cleo | Drew
Valid arrangement 2:   Bo | Cleo | Ava | Drew

(Any other arrangement either puts Ava on an end or violates the Bo < Cleo < Drew order.)

Step 3 — Who is always on the far right?

In EVERY valid arrangement, Drew is at the far right (position 4).

Answer: Drew