AP BIOLOGY

Detailed explanation-1: -The divisibility rule of 7 states that, if a number is divisible by 7, then “the difference between twice the unit digit of the given number and the remaining part of the given number should be a multiple of 7 or it should be equal to 0”. For example, 798 is divisible by 7. Explanation: The unit digit of 798 is 8.

Detailed explanation-2: -Missing numbers are the numbers that have been missed in the given series of a number with similar differences among them. The method of writing the missing numbers is stated as finding similar changes between those numbers and filling the missing terms in the specific series and places.

Detailed explanation-3: -Divisibility Rule of 23 Rule: For a number to be divisible by 23; Multiply the last digit by 7 and add the result to the number formed by removing the last digit. If the final result is divisible by 23, then the given number will also be divisible by 23.