How many three-digit integers between 311 and 401, exclusive, are divisible by 3 when the tens digit and the hundered digit are switched?
Choose the correct choice from the following choices:	A) 30	B) 19	C) 22	D) 3	E) 90
Answer is 30   No of digits between 311 and 401 (exclusive) = 401-311-1= 
<gadget id="calculator">401-311-1</gadget>
<output>89</output>
89   No Intergers divisble by 3=~ 89/3 ~ 30   Divsiblivity rule for 3 is Sum of all digits must be divisble by 3. It doesn't matter if hundred digit and tens digits are switched.   e.g 372 is divisble by 3 (becae 3+7+2= 
<gadget id="calculator">3+7+2</gadget>
<output>12</output>
12 (divisble by 3))   switch digits 732 also divisble by 3 (becae 7+3+2= 
<gadget id="calculator">7+3+2</gadget>
<output>12</output>
12 (divisble by 3))   Divsiblivity rule for 3 is Sum of all digits must be divisble by 3. It doesn't matter if hundred digit and tens digits are switched.   You have right. So it is enough to proceed like usual to find the numbers in a given range that are divisible by 3. So 399-312/3 +1=30.   30nswer : 30
<result>A</result>
How many three-digit integers between 311 and 401, exclusive, are divisible by 3 when the tens digit and the hundered digit are switched?