Each table in a library can seat up to 5 people. There are enough tables for 75 people. How many tables are there in the library?​

15 tables

Step-by-step explanation:

75/5 = 15

There are 15 tables in the library.

Step-by-step explanation:

You know this because you know the library holds 75 people and you know how many people can sit at a table so to find the answer you divide 75 by 5 and you get 15. To check this you can multiply 15 by 5 and you will get 75.  

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.

the answer is b