The cart total

Problem

A shopping cart keeps its data in two lists of the same length: prices has the price in dollars of each item, and counts how many of that same item you are buying. The position joins them: the price at position 0 goes with the count at position 0.

Write a function that takes the two lists and returns the total to pay: the sum of price times count for each item. With both lists empty the total is 0.

Examples

• [10, 20], [2, 1] → 40

• [5], [3] → 15

• One item with a count of 0

  [7, 3], [0, 4] → 12

Besides these, the challenge has hidden tests that are revealed when you submit your solution.

You start with this

def cart_total(prices, counts):
    pass

function cartTotal(prices, counts) {
}