the square of a whole # is between 1,500 & 1,600. The # must be between?

Question

a.30 & 35
b.35 & 40
c.40 & 45
d.45 & 50

please explain your answer & how u got that answer...

Answer 1

1600 is 40 squared. Has to be B, since it's the only one that has 40 as the second number.

Answer 2

1600 is 40 squared (easy to spot, since it starts with "16" which you know is a perfect square). So the number can't be 40 or higher. Thus c and d are eliminated. It would seem "B" is the right choice since the range ends in 40, but we don't actually know off hand if everything in "a" will fit into the range too when squared. But 35 squared is 1225, so nothing in "a" can have the square fit into the range 1500 and 1600. So "B" is the correct choice.

Answer 3

Answer: 35 and 40

Notice 4^2 = 16, so 40^2 = 1600. Therefore, 40 in the high range, which solves the question.

Answer 4

The square of a whole numbe is between 1500 and 1600. Work backward, take the sqrts of each number: Sqrt (1500) = 38.73 and sqrt (1600) = 40. Since we need a whole number, we are left with 39. 39^2 = 1521. That means letter b is your answer.

Answer 5

1600 is a perfect square and = 40 * 40.

Thus, the 35 in a. is too small...eliminate.
The # must be LESS THAN 40, so elim. c and d.
b. is the best answer.

Test it.
35^2=1225 and 40^1600.
A number whose square is between 1500 and 1600 will be entirely within that set.
Done!

Answer 6

The square root of 1500 is 38.73.
The square root of 1600 is 40.
The only whole number between 38.73 and 40 is 39...bingo.

Answer 7

b)
Sqrt1600 =40 , sqrt 1500 =38.73
So the number is greater then 38 and smaller than 40

Answer 8

I know that 40x40 is 1,600, and that's the maximum of the range you gave, so it would have to be answer B, between 35&40.