the largest prime 1- digit number 

the smallest prime 2 - digit number

in a 4-digit number, the ones digit is the possible largest number, the hundreds digit is the smallest odd number and the tens digit is 1 more than the hundreds digit. The thousands digit is the sum of the hundreds and the tens digit. Find the number

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In a 4-digit number, the ones digit is the possible largest number, the hundreds digit is the smallest odd number and the tens digit is 1 more than the hundreds digit. The thousands digit is the sum of the hundreds and the tens digit. Find the number.
Answer: The number is 

In a 4- digit number. The ones digit is the possible  largest number, the hundreds digit is the smaller odd number and the tens digit is 1 more thann the hundreds digit. The thousands digit is the sum of the hundreds and the tens digit. Find the number.

if a is the largest prime number less than 1000 , then what is the smallest non - zero natural number b so that a+b is also a prime number?

Answer: b = .......

the largest prime number less than 20

write the largest number from the one two and three digit 

using each of a digit 3,4,5 and 6 exactly once to form two 2 digit numbers .what is the different between the largest possible product and the smallest possible product of two such number