Ii) find the smallest positive integer p such that 1440p is a perfect cube.

Any negative number would work as negative numbers are smaller than positive numbers.

Also, any number that is positive less than 0.271 will work. You can move the decimal point over 3 spots to get 271 and then think of a positive number less than 271 (say the number 180). So 0.180 is less than 0.271

It sounds like you were given a list of answer choices. Without them, it's impossible to say which answer your teacher wants. But you can use the guidelines I provided above to get the answer.