Which of the following is/are EQUAL to 224 in radix-5 (i.e., base-5) notation?

Key step: convert 224 (base 5) to decimal: 2×5^2 + 2×5 + 4 = 64.

• 64 in radix-10 — equals 64 decimal.

• 100 in radix-8 — equals 64 decimal (1×8^2).

• 121 in radix-7 — equals 64 decimal (1×7^2 + 2×7 + 1).

Therefore, the representations equal to 224 in base 5 are: 64 in radix-10, 100 in radix-8, and 121 in radix-7. (For reference, 50 in radix-16 equals 80 decimal, so it does not match.)