A 3-digit number 43 is added to another 3-digit number 984 to give a 4-digit number 137, which is divisible by 11. Then, ( + ) = ?

A 3-digit number 43 is added to another 3-digit number 984 to give a 4

1.	A 3-digit number 43 is added to another 3-digit number 984 to give a 4-digit number 137, which is divisible by 11. Then, ( + ) = ?
Answer» 4 a 3 \| 9 8 4 } ==> a + 8 = b ==> b - a = 8 13 b 7 \| Also, 13 b7 is divisible by 11 (7 + 3) - (b + 1) = (9 - b) (9 - b) = 0 b = 9 (b = 9 and a = 1) (a + b) = 10.