1
2 is prime, its only factors are one and itself.
3
18.You can answer it easily by considering three places for three digits of the number.The hundreds place cannot take zero hence it can take 2 values.The next two places can take all the three digits.Hence the total number of ways is 2*3*3=18.
875
92.
The greatest 2-digit even number is 98
111,112,121,211,122,212,221,222,113,131,311,133,313,331,333,223,232,322,233,323,332,123, 132, 213, 231, 312, 321
Since the greatest digit is 9 and the greatest 2-digit number is 99, the product of them is 891.
The greatest sommon factor of 10 -2 and 14 is 2.
Just arrange all numbers from highest to lowest, from left to right.So it would be:7532
There is no such number. If N were the greatest even number then N+2 would be a greater even number. So N could not be the greatest even number.
By simply ordering the digits the largest is .5420