CAT (QA) PYQs

For a 4-digit number (greater than 1000), sum of the digits in the thousands, hundreds, and tens places is 15. Sum of the digits in the hundreds, tens, and units places is 16. Also, the digit in the tens place is 6 more than the digit in the units place. The difference between the largest and smallest possible value of the number is

The sum of digits of the number $(625)^{65} \times (128)^{36}$, is

The sum of all the digits of the number $(10^{50}+10^{25}-123)$, is