Integers ques...pls help!!

[Rocky Balboa]

Please help understand if there is a better way to handle such questions..thanks in advance!

How many integers from 101 to 800, inclusive, remains the value unchanged when the digits were reversed?
(A) 50
(B) 60
(C) 70
(D) 80
(E) 90

[messi10]

Hi,

What is the source of this question?

Thanks

Sunil

[adrielfrederick]

The first and last digits should be the same for the value to not change.

i.e The three digit number should be in the format xyx

where x- can take values between 1 and 9 and y between 0 and 9

Therefore the answer would be 9 *10=90

[messi10]

Hi adrielfrederick,

The first and last digit cannot be between 1 and 9 as the range is between 101 and 800.

However, before we can answer this question we need to make sure that it is not from a banned source and that is why I have asked Deepti to specify it.

Thanks

Sunil

[jnelson0612]

Thanks Sunil. We do indeed need the source of this question.

[karthicramesh19]

Hi,
Lets first consider digits from 101 to 200 inclusive.
The possible numbers in this range are 101,111,121,131,141,151,161,171,181, & 191. This makes a total of 10.
Similarly, 201 to 300, 301 to 400, 401 to 500, 501 to 600, 601 to 700 and 701 to 800 each have 10 numbers.
Therefore, that's a total of 10*7 = 70 numbers, hence Ans C.

[biswas_sandeep]

I agree with Karthic's answer. It should be C --> 70.

Deepti can you pls confirm the correct answer.

[tim]

it looks like C is indeed correct..