What is the smallest four-digit number that is divisible by 15?

1,005Correct answerYour answer1,010Correct answerYour answer1,015Correct answerYour answer1,025Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer A

Correct answer: A

Divisible by 15 means divisible by 3 and by 5.
It must end in 0 or 5: try 1,000 (digit sum 1, fails 3), then 1,005 (digit sum 6, passes).
$1{,}005 = 15 \times 67$ .

Worth noting

1,010, 1,015 and 1,025 pass the test for 5 but have digit sums 2, 7 and 8, so they fail the test for 3.

Ten questions from Number System, at your own pace.

Ten questions from Number System, at your own pace.

Explanation