Digit Manipulation: Changing Units (+7) and Tens (-8) in 191

To solve the problem, we will focus on these steps:

• Step 1: Identify the digits of the number 191.
  The number 191 consists of:
  • Units digit: 1
  • Tens digit: 9
  • Hundreds digit: 1
• Step 2: Increase the units digit by 7.
  The units digit is 1. Adding 7 results in 8.
• Step 3: Decrease the tens digit by 8.
  The tens digit is 9. Subtracting 8 gives 1.
• Step 4: Reconstruct the new number using the modified digits.
  The modified digits are:
  • Units digit: 8
  • Tens digit: 1
  • Hundreds digit (unchanged): 1
  Thus, the new number is $118$.

Therefore, the resulting number after these changes is $118$.