Question

6+5=111, 2+1=31, 4-1=43 then 199-8= ?

Answer 1

6+5=111, 2+1=31, 4-1=43.

Add 6 and 5 to produce 11. Add also means multiply the result by 10 and add 1: 110+1=111.

Add 2 and 1 to produce 3. Add also means multiply the result by 10 and add 1: 30+1=31.

Subtract 1 from 4 to produce 3. Subtract also means multiply the minuend (4) by 10 and add to the result of the subtraction: 40+3=43.

Guess that 199-8 follows the latter logic:

Subtract 8 from 199 to produce 191. Subtract also means multiply the minuend (199) by 10 and add to the result of the subtraction: 1990+191=2181.