A 55-digits positive integer ab3cd is a multiple of 225
factorizing 225 we get = 5*5*3*3
since ab3cd is a multiple of 225 = ab3cd is divisible by --3, 9, 5, 15, 25, 75, 45, 225
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ab3cd to be divisible by 225 must be divisible by all factorslet's see the answer choice--
A.98325
--this is the correct answer
(correct)B.97325
-adding digits to check the divisibility by 3 = 9+7+3+2+5 = 26 (not the multiple of 3)
-so not divisible by 3
-hence, not the multiple of 225
(incorrect)C.96320
-adding digits to check the divisibility by 3 = 9+6+3+2+0 = 20 (not the multiple of 3)
-so not divisible by 3
-hence, not the multiple of 225
(incorrect)D.95325
--adding digits to check the divisibility by 3 = 9+5+3+2+5 = 24 (multiple of 3)
-so divisible by 3
let's check for 9 --adding digits to check the divisibility by 9 = 24 (not the multiple of 9)
-not divisible by 9
-hence, not the multiple of 225
(incorrect)E.95320
---adding digits to check the divisibility by 3 = 9+5+3+2+0 = 19 (not the multiple of 3)
-not divisible by 3
-hence, not the multiple of 225
(incorrect)