The most accurate way would be the fourth answer, because to estimate 66% of 47 you need to round both as closely as possible. 66% rounds closest to 2/3, and 47 is closest to 48
Are you sure the options are what u have written above? because sqrt of 5x=sqrt of 5x,
sqrt of 20x=2•sqrt of 5x,and sqrt of 80x= 4•sqrt of 5x..
The probability of an event is given by the number of favorable outcomes divided by the total number of outcomes. Here the event is the alarm clock running out of power. There are 24 hours during which the power can go out. You are asleep during 8 of these. A "favorable" outcome in this case is the power going out while you are sleeping -- that is, during one of those 8 hours. This makes the probability that the power goes out while you are sleeping 8/24.
Multiply 3 by the denominator, then add the numerator. Then we keep the original denominator.
So we get:
3 x 5 = 15 + 3 = 18
we get:
18/5