These are exercises in myprogramminglab for python and i think the simpler the code the better:

1.Associate the sum of the non-negative values in the list numbers with the variable sum.

2.In the following sequence, each number (except the first two) is the sum of the previous two numbers: 0, 1, 1, 2, 3, 5, 8, 13, .... This sequence is known as the Fibonacci sequence.

We speak of the i'th element of the sequence (starting at 0)-- thus the 0th element is 0, the 1st element is 1, the 2nd element is 1, the 3rd element is 2 and so on. Given the positive integer n, associate the nth value of the fibonacci sequence with the variable result. For example, if n is associated with the value 8 then result would be associated with 21.

3.A triangular number is a number that is the sum of the integers from 1 to some integer n. Thus 1 is a triangular number because it's the sum of the integers from 1 to 1; 6 is a triangular number because it's 1+2+3=6.

Given the non-negative integer n, create a list of the first n triangular numbers. Thus is n was 5, the list would be: [1, 3, 6, 10, 15]. Associate the list with the variable triangulars.