Anumber is chosen at random from the numbers -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5. then the probability that square of this number is less than or equal to 1 is

ANSWER:  

The probability of getting a number whose square is less than or equal to 1 is

SOLUTION:

Given, a number is chosen at random from the numbers -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5.

Then we have to find the probability that square of this number is less than or equal to 1 is.

We know that, probability of any event is number of favorable outcomes divided by total possible outcomes.

Now, let us see the favorable outcomes,

From the given set, there exists only three numbers whose square is less than or equal to 1, they are -1, 0, 1. Remaining all numbers have their squares greater than 1.

So, number of favorable outcomes = 3

And, Total number of possible outcomes = 11 [ since there are 11 numbers]

Now, probability =

=

Hence, the probability of getting a number whose square is less than or equal to 1 is

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.