Answer: Option C. -> 1764 : C The square of 42 should have 4 in the unit place (since the square of 2 is 4). 84 is too small to be square of 42. So, option 3 is correct. Alternatively, 42 can be multiplied with itself to give the result.
Answer: Option B. -> False : B ((x2)2)2=x8 and (x3)3=x9 As we can see the square of a square of a square has a total power of 8 whereas the cube of a cube has a total power of 9. Thus, they are not equal.
Answer: Option A. -> True : A Square of a perfect cube is another perfect cube. Let us take a number, n. Its cube isn3. Square of this cube would be a perfect square given by (n3)2, which can also be written as(n2)3, a perfect cube.
Question 115. A division is the inverse operation of a square.
Answer: Option B. -> False : B The square root is the inverse operation of a square. A division is the inverse operation of multiplication, not of a square.
Question 116. Which of the following will have 1 in its unit's place?
Answer: Option B. -> 1612 : B The square of a number will end in 1,if the digit in the units place is either1 or 9. We know that12=1and92=81. Among the given options, 161 has 1in its units place. Hence,(161)2will have 1 in its unitsplace.
