What is the smallest number of 4 digits which is exactly divisible by 7?
Answer: B
The smallest 4-digit number is 1000. We divide 1000 by 7 to find the remainder. \(1000 = 142 \times 7 + 6\). The remainder is 6. To find the smallest 4-digit number divisible by 7, we need to add a number to 1000 to make it a multiple of 7. The number to be added is \(7 - \text{remainder} = 7 - 6 = 1\). The required number is \(1000 + 1 = 1001\).