Question 12

State True or False. The number of four digit numbers which are perfect squares and in which the first two digits are equal to each other and the last two digits are equal to each other is 2


Correct Answer: False

Solution

Such a number is $$\overline{aabb} = 1100a + 11b = 11(100a + b)$$, so 11 divides it and $$100a + b$$ must be 11 times a square, i.e. $$a + b = 11$$ and $$\overline{aabb} = 121(9a + 1)$$. The only digit $$a$$ making $$9a + 1$$ a perfect square is $$a = 7$$, giving $$7744 = 88^2$$. There is only 1 such number, so the statement is False.

Was this solution helpful?

Get AI Help

50,000+ JEE Students Trusted Our Score Calculator

Predict your JEE Main percentile, rank & performance in seconds

Ask AI