Given that 29a031 × 342 = 100900b02 where a and b denote two missing
digits, what is the value of a + b ?
Choices:
A) 7	B) 8	C) 9	D) 10	E) 11
Recall the tests for divisibility by 9 and by 11. Since 342 is divisible by 9, the number   100900b02 is as well. So b has to be 6. But then 100900b02 is divisible by 11. Since 342 is   not divisible by 11, we deduce 29a031 must be divisible by 11. So a has to be 5, and a + b = 11.   correct answer 11
<result>E</result>
Given that 29a031 × 342 = 100900b02 where a and b denote two missing
digits, what is the value of a + b ?