30 points.. ! i don't understand what to do with this bit confused.

  Eh, here's my best try for a table:

                       Like tv           don't like tv       total
Like reading:     70                     10                 80
 Don't like read. 20                     30               50  
      total               90                    40               130

The percentage of students that like tv as well as reading is- 70 divided by 130 which gives you .538 which in percentage is 53.8%.

The probability of a student that does not prefer to watch tv as also does not like to spend their time reading is 30 over 40 which can be simplified or reduced to 3 over 4. [30/40 reduced to 3/4]

Hope this somehow helped you :)

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.