Question

If the positions of the first and the second digits of each of the numbers are interchanged, in how many numbers thus formed will the first digit be a perfect square? (‘1’ is also a perfect square)

• A. One
• B. Two
• C. Three
• D. Four
• E. Five

Answer 1

The correct option is B

Two

Given that five three-digit numbers are:

356 497 812 739 264

The positions of the first and the second digits of each of the numbers after being interchanged are:

536 947 182 379 624

Given that ‘1’ is also a perfect square, so only in 947 and 147, the first digit is a perfect square.