Question

Which of the following will be the last digit of the second highest number after the positions of the each digit in each number is reversed?
$738,429,156,273,894$
A) $1$
B) $2$
C) $4$
D) $7$

Answer 1

Hint: We are given a series of numbers and we are asked that if the position of digits in the number are reversed then what will be the value of the last digit of the second highest number. For this purpose we will reverse the digits of each number. All numbers are three digits so we will exchange the first digit with the last digit and on exchanging the values we get the new numbers and then we can arrange the number according to the ascending order from smallest to largest. To arrange the numbers first compare the first digit then second digit and then third digit after arranging we will check the last digit of the second highest number.

Complete step-by-step answer:
Step1: We are given the series of numbers as $738,429,156,273,894$. Firstly we will reverse the digits as these are three digit numbers then we will exchange the digits the first and the last.
Hence on exchanging the digits new numbers formed will be:
$837,924,651,372,498$
Step2: Now we will arrange these numbers according to the ascending order. To arrange in ascending order4 we will start from lowest and go to highest. By examining the first digit of each number we will arrange them:
$372 < 498 < 651 < 837 < 924$
Step3: Now we will check the last digit of the second highest number. In this second highest number is $837$ and the last digit of this number is i.e. at unit place is $7$.

Hence, option (D) is the correct answer.

Note: In such types of questions students get confused about how to reverse the digits in three digit numbers and they make mistakes in it. So for that exchange the first digit with the last digit and leave the middle digit unchanged for 3 digit numbers. The middle term remains unchanged for odd digit numbers. They also make mistakes in arranging in ascending order just keep in mind that in arranging first count the number of digits in each number and then compare the digits from first place.