Which code opens the far left cabinet?

Which code opens the far left cabinet?

• A. 1234
• B. 2140
• C. 9876
• D. 0000

Answer: (B)

This type of problem often uses a simple rule that only one code satisfies. Here the rule is that the digits in the code sum to a prime number. Checking each code: 1234 sums to 10 (not prime); 2140 sums to 7 (prime); 9876 sums to 30 (not prime); 0000 sums to 0 (not prime). Since only 2140 has a prime digit sum, it fits the rule and opens the far left cabinet. The other options fail because their digit sums aren’t prime.

This type of problem often uses a simple rule that only one code satisfies. Here the rule is that the digits in the code sum to a prime number. Checking each code: 1234 sums to 10 (not prime); 2140 sums to 7 (prime); 9876 sums to 30 (not prime); 0000 sums to 0 (not prime). Since only 2140 has a prime digit sum, it fits the rule and opens the far left cabinet. The other options fail because their digit sums aren’t prime.