Question 7
How many seven-digit numbers $\overline{A623B4C}$ make both $\overline{47A1B25}$ and $\overline{A623B4C}$ divisible by 3? A, B and C are digits.
Examples:
• 2623341 qualifies because 4721325 and 2623341 are both divisible by 3.
• 4623145 does not qualify: 4741125 is divisible by 3, but 4623145 is not.
Examples:
• 2623341 qualifies because 4721325 and 2623341 are both divisible by 3.
• 4623145 does not qualify: 4741125 is divisible by 3, but 4623145 is not.