Solutions for https://github.com/karan/projects/

ChangeReturnType.fs

let coins = [
    "quarter", 0.25m; 
    "dime", 0.10m; 
    "nickel", 0.05m; 
    "penny", 0.01m 
]

let rec giveChange (change : decimal) =
    let coin = coins |> List.tryFind (fun (_, coinValue) -> change >= coinValue)
    match coin with
    | Some (name, coin) ->
        Console.WriteLine name  
        giveChange (change - coin)
    | None -> ()

let cost = 1.10m
let amountGiven = 2.00m
giveChange (amountGiven-cost)

CheckIfPalindrome.fs

open System
open System.Linq

let Main() = 
    let isPalindrome (text : string) = 
        let reversedText = 
            text
            |> Seq.fold (fun acc char -> (string) char + acc) ""
        text = reversedText
    let inputText = Console.ReadLine()
    Console.WriteLine (isPalindrome inputText)
    ()

Main()

CountVowels.fs

open System
open System.Linq

let enumerateVowels text = 
    let vowels = [| 'a'; 'e'; 'i'; 'o'; 'u' |]
    let charIsVowel char = Seq.exists ((=) char) vowels
    text
    |> Seq.groupBy char
    |> Seq.where (fst >> charIsVowel)
    |> Seq.iter (fun (char, seq) -> Console.WriteLine("{0}: {1}", char, seq.Count()))

let Main() = 
    Console.Write "Enter a word: "
    let inputText = Console.ReadLine()
    enumerateVowels inputText

Main()

CountWordsInAString.fs

open System
open System.IO
open System.Linq

let delimiters = [| " "; Environment.NewLine |]
let countWords (sentence : string) = 
    sentence.Split(delimiters, StringSplitOptions.RemoveEmptyEntries).Count()

let Main() =
    Console.Write "Enter file path: "
    let path = Console.ReadLine()
    let wordCount = 
        File.ReadLines(path)
        |> Seq.sumBy (fun line -> countWords line)
    Console.WriteLine("Word Count for: {0}", wordCount)
    ()

Main()

DecimalToBinary.fs

let rec convert number =
    match number with
    | 0 | 1 -> string number
    | _ ->
        let remainder = string (number % 2)
        (convert (number / 2)) + remainder

Console.WriteLine (convert 10)

QuoteTracker.fs

open System
open System.Text.RegularExpressions
open System.Net.Http

type Stock = {
    ask : string
    change : string
    companyName : string
}

let DownloadString (requestUri : string) =
    use client = new HttpClient()
    client.GetStringAsync(requestUri).Result

let HydrateStocks (response : string) =
    let records = response.Split([|Environment.NewLine|], StringSplitOptions.RemoveEmptyEntries)
    seq {
        for record in records do
            let fields = record.Split ','
            yield { 
                companyName = fields.[0].Replace("\"", "")
                ask = fields.[1];
                change = fields.[2]
            }
    }

let Main = 
    Console.Write "Enter the stock ticker symbols to track (delimitered by '+'): "
    let inputText = Console.ReadLine()
    let response = DownloadString(String.Concat("http://finance.yahoo.com/d/quotes.csv?s=", inputText, "&f=nac1"))
    let stocks = HydrateStocks response
    for stock in stocks do
        Console.WriteLine stock.companyName
        Console.WriteLine stock.ask
        Console.WriteLine stock.change
        if stock.change.Contains "-" then
            Console.ForegroundColor <- ConsoleColor.Red
            Console.WriteLine "▼"
        else 
            Console.ForegroundColor <- ConsoleColor.Green
            Console.WriteLine "▲"
        Console.ForegroundColor <- ConsoleColor.Gray
        Console.WriteLine "---"
    ()

ReverseAString.fs.cs

open System
open System.Linq

let rec Main() =
    Console.Write "Enter some text: "
    let inputText = Console.ReadLine()
    if inputText = "exit" then 
        ()
    else
        let reversedText = 
            inputText 
            |> Seq.fold (fun acc character -> (string) character + acc) ""
        Console.WriteLine reversedText
        Main()

Main()

RssFeedCreator.fs

open System
open System.Xml
open System.ServiceModel.Syndication

let Main = 
    use reader = XmlReader.Create("http://toddmotto.com/feed.xml")
    let feed = SyndicationFeed.Load(reader)
    for item in feed.Items do
        Console.WriteLine item.Title.Text
    ()