A safe has a 4 digit lock code that does not include zero as a digit and no digit is repeated what is the probability that the l
1 answer:
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Answer:
It is divisible by 11 and (a + b) !
Step-by-step explanation:
Given a two digit number , the digits written in reverse order is
.
Note that a two digit number ab = 10a + b.
For example: 24 = 10(2) + 4
Similarly, ba = 10(b) + a
Now, the sum of the numbers ab and ba = 10a + b + 10b + a
= 11a + 11b
= 11(a + b)
Hence, the sum of any two digit number ab and the reverse of the number ba, is divisible by 11 and (a + b).
Hence, proved.