--- The 3.12 basically means 3.1212121212.....in other words the 12 can go on forever. and the answer is the first option 3 4/33.To get this leave the 3 alone --- because U don't need 2 do anything with it and do 4/33 and U get 0.12 --- put the 3 back in and U have 3.12.
for question 4 An irrational number can't be expressed as a ratio between 2 numbers and it can't be written as a simple fraction because there isn't a finite number of numbers when written as a decimal. Instead, the numbers in the decimal would go on forever without repeating.A good example of this is pi.so the answer is option 4 pi.