Find the values of X and Y in the 4×4 grid where each row and column follows a specific...
Texas Instruments technical mcq question, verified with a worked answer. Free to practise - no sign-up.
Find the values of X and Y in the 4×4 grid where each row and column follows a specific arithmetic pattern. The grid contains:
- Row 1: 1, 3, 5, 7
- Row 2: 4, 8, X, 16
- Row 3: 7, 13, 19, 25
- Row 4: 10, 18, Y, 34
Determine X and Y.
(Clock Problem)
13. Clock from a flea market
A person bought a clock from a flea market and set it at 10 AM. He notices that the watch gains 5 seconds in 3 minutes.
If it shows 7:15 in the afternoon on the same day, what is the correct time?
Show answer & explanation
The clock gains 100 seconds per hour. Over 9 true hours (from 10:00 AM to 7:00 PM), it gains 900 seconds = 15 minutes, showing 7:15 PM. Thus the correct time is 7:00 PM.
Step-by-step Derivation:
Step 1: Rate of gain = 5 seconds / 3 minutes = 100 seconds per 60 minutes (1 hour).
Step 2: From 10:00 AM to 7:00 PM is 9 hours.
Step 3: Total gain in 9 hours = 9 * 100 = 900 seconds = 15 minutes.
Step 4: At 7:00 PM true time, the clock reads 7:00 + 15 min = 7:15 PM.
Step 5: Hence, when it reads 7:15 PM, the correct time is 7:00 PM.