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If it is possible to make a number which is perfect square of a two-digit odd number with the second, the sixth and ninth digits of the number 187642539. which of the following is the digit in the unit’s place of that two-digit odd number?
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- 1
- 7
- 9
- No such number can be made
- More than such number can be made
Correct Option: B
The specified digits are 8, 2 and 9. Now, we know a perfect square number does not have 8 and 2 at unit’s place. Therefore, we can make only two three-digit numbers from it, i.e., 829 and 289. Among these two numbers, 289 is a perfect square number, i.e., square of 17. Thus, unit’s digit is 7 and ten’s digit is 1.