198.
99 + 9 = 108
199
They are: 89+97 = 186
9797 is the largest two digit prime number.
The smallest two-digit composite number is 10, which is the product of 2 and 5. The largest two-digit composite number is 99, which is the product of 3 and 33. To find the sum of the smallest and largest two-digit composite numbers, we add 10 and 99, resulting in 109.
It is: 79+83+89+97 = 348
679 is the product of the largest single-digit prime number and the largest two-digit prime number.
98 is the largest two digit number divisible by 7.
9 and 99
49
The units digit of a two digit number exceeds twice the tens digit by 1. Find the number if the sum of its digits is 10.
The largest three-digit number whose digits sum to 13 is 940. This is because the number must start with the highest possible digit, which is 9. To achieve a digit sum of 13, the next two digits must total 4, and the highest combination is 4 and 0, giving us 940.