Question

Prajna is listing squares of two-digit numbers in such a way that the digit in their units place is 6.

Answer 1

Answer:

2 (option B)

Question:

Prajna is listing squares of two-digit numbers in such a way that the digit in their units place is 6.

How many numbers should he have listed?

a) 9 b) 2 c)18 d) 20

Step-by-step explanation:

We would find the perfect squares that are two digit numbers

For two digit perfect squares:

Largest two digit number= 81 = 9²

Smallest two digit number= 16 = 4²

Total Two digit number perfect squares = Highest number - lowest number + 1

= 9-4+1 = 6

There are 6 two digit perfect squares

Next, we have to find how many of them have 6 in their units place.

The rule to be applied: If a number has 4 or 6 in the unit place, then its square has 6 in the units place.

Following this, the possibilities are 4², 6².

We have two of such numbers.

Therefore, he would have listed 2 numbers.