Concept – Divisibility of a number Divisibility by 2 — A number is divisible by 2 if the unit digit is zero or divisible by 2. Ex. – 2, 4, 8, 16, 18 etc. are all divisible by 2. Divisibility by 3 — A number is divisible by 3 if the sum of digits of the number is divisible by 3. Ex. – if 43n25 is divisible by 3 then find the minimum value n Sol. 4+3+n+2+5 is divisible by 3 So n=1,4,7 Minimum value of n=1 Divisibility by 4 — A number is divisible by 4 if the number formed by the last two digits is divisible by 4 . Ex. – 56248 is divisible by 4 since 48 is divisible by 4. Divisibility by 5 — A number is divisible by 5 if unit’s digit is 0 or 5. Ex. – 1225, 13750, 245 etc. are all divisible by 5. Divisibility by 7 — The unit digit of given number is doubled and then it is subtracted from the number obtained after omitting the unit digit. If the remainde...