A 3-digit number 4a3 is added to another 3-digit number 984 to give a 4-digit number 13b7, which is divisible by 11. Then, (a + b) = ? Select the correct option.
A) 10	B) 11	C) 12	D) 15	E) 16

Rationale: 4 a 3 | 9 8 4 } = = > a + 8 = b = = > b - a = 8 13 b 7 | also , 13 b 7 is divisible by 11 = > ( 7 + 3 ) – ( b + 1 ) = ( 9 – b ) ( 9 – b ) = 0 b = 9 ( b = 9 and a = 1 ) = > ( a + b ) = 10 . answer a
Answer: A