Consider four digit numbers for which the first two digits are equal and the last two digits are also equal. How many such numbers are perfect squares?
A. 2
B. 4
C. 0
D. 1
E. 3
Answer: Option D
Solution(By Examveda Team)
Any four digit number in which first two digits are equal and last two digits are also equal will be in the form 11 × (11a + b) i.e. it will be the multiple of 11 like 1122, 3366, 2244, . . . .Now, let the required number be aabb.
Since aabb is a perfect square, the only pair of a and b that satisfy the above mentioned condition is a = 7 and b = 4 Hence, 7744 is a perfect square
This Question Belongs to Arithmetic Ability >> Number System
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Comments ( 1 )
Related Questions on Number System
Three numbers are in ratio 1 : 2 : 3 and HCF is 12. The numbers are:
A. 12, 24, 36
B. 11, 22, 33
C. 12, 24, 32
D. 5, 10, 15
you have given the wrong form for 4 digit no.
the correct form for 4 digit no. whose first 2 digits are same and last 2 digits are same should be 11*(100a+b)