1.
Which of the following is a perfect square number?
Correct Answer
A. 2401
Explanation
2401 is a perfect square number because it is the square of 49. The square root of 2401 is 49, which means that 49 multiplied by itself equals 2401.
2.
Square of Which of the following would end with digit 1?
Correct Answer
B. 161
Explanation
The square of a number will end with the digit 1 if the number itself ends with the digits 1, 9, or 5. In this case, the number 161 ends with the digit 1, so its square will also end with the digit 1. Therefore, the square of 161 will end with digit 1.
3.
The squares of which of the following would be odd numbers?
Correct Answer
C. 7775
Explanation
The square of a number is odd if and only if the number itself is odd. Therefore, the square of 7775 would be an odd number.
4.
Without adding, find the sum: 1 + 3 + 5 + 7 + 9
Correct Answer
D. 25
Explanation
The sum of consecutive odd numbers can be found by using the formula n^2, where n is the number of terms. In this case, there are 5 terms (1, 3, 5, 7, 9), so the sum is 5^2 = 25.
5.
Without doing any calculation, find the numbers which are surely perfect squares.
Correct Answer
D. 441
Explanation
The number 441 is surely a perfect square because it is the square of 21. The other numbers cannot be determined without calculation.
6.
How many natural numbers lie between 18^{2} and 19^{2}?
Correct Answer
C. 36
Explanation
The question asks for the number of natural numbers between 182 and 192. To find the answer, we subtract 1 from 192 to exclude it from the count, and then subtract 182 from the result to exclude it as well. The remaining number is 9. Therefore, there are 9 natural numbers between 182 and 192.
7.
Which of the following is not a perfect square?
Correct Answer
C. 1128
Explanation
A perfect square is a number that can be expressed as the product of an integer multiplied by itself. To determine if a number is a perfect square, we can take its square root and check if it is an integer. In this case, the square root of 1156 is 34, the square root of 361 is 19, the square root of 1128 is approximately 33.57 (not an integer), and the square root of 1681 is 41. Therefore, 1128 is not a perfect square.
8.
A perfect square can never have the following digit at
ones place
Correct Answer
D. 3
Explanation
A perfect square can never have the digit 3 at its ones place because the square of any number ending in 3 will always have a ones digit of 9. For example, 3^2 = 9, 13^2 = 169, 23^2 = 529, and so on. Therefore, a perfect square can never end with the digit 3.
9.
196 is the square of
Correct Answer
C. 14
Explanation
The correct answer is 14 because when you multiply 14 by itself, you get 196. In other words, 14 squared is equal to 196.
10.
A number ending in 9 will have the units place of its square as
Correct Answer
C. 1
Explanation
When a number ending in 9 is squared, the units place of the square will always be 1. This is because when any number ending in 9 is multiplied by itself, the units digit of the product will always be 1. For example, 9 squared is 81, 19 squared is 361, and so on. Therefore, the correct answer is 1.