3.
Texas Instruments technical mcq question, verified with a worked answer. Free to practise - no sign-up.
A luxury shoe store**
A luxury shoe store wants to open a new franchise in a city. The store owner decides to install display units on all four walls of the store by hiring a fixture maker. However, on completion of the installation, the store owner complained saying that a portion of a high wall was missing display units.
The manager of the fixture company asked the workers as to whose fault it was but the workers refused to say anything. Hence, the manager decides to question the workers and the following facts are ascertained:
(1) No one other than W1, W2, W3 was involved in installing displays.
(2) W3 never does a job without the help of W1 (and possibly others) as an accomplice.
(3) W2 does not know how to install fixture on high walls.
Is W1 innocent or guilty?
**
Show answer & explanation
W2 cannot work on high walls. Therefore, any work on high walls must involve W1, W3, or both. Since W3 never works without W1, W1 is necessarily involved in the faulty installation.
Step-by-step Derivation:
Step 1: Fact 3 states W2 cannot install fixtures on high walls, so W2 could not have done the job alone.
Step 2: Therefore, the high wall work was performed by either W1 alone, or W3.
Step 3: Fact 2 states W3 never works without W1 as accomplice.
Step 4: In all valid scenarios, W1 was actively involved. Thus W1 is guilty.