1. Briefly describe Ada Lovelace's and Alan Turing's contributions
to computing. How did the invention of logarithms help computing?
*For extra credit:* describe one more event from the history of
computing.

Ada Lovelace was the world's first programmer. She wrote "programs" for the Babbage's computing machine. Alan Turing designed a general model of computation; during the Second World War, he helped design a specialized computer nicknamed "Bomb" that successfully decoded German military codes. Logarithms made computations easier because they enabled to reduce multiplication to an easier operation - addition. The use of logarithms in computing is based on the fact that log(a*b) = log(a) + log(b). So, to compute a*b, we can do the following: 1) find log(a) and log(b), 2) add these two logarithms, thus computing s = log(a)+ log(b); and 3) find a number whose logarithm is equal to this sum s. This number will be exactly a*b. This idea formed the base of a slide rule, which for several centuries was the main computational tool of engineers.2. At UTEP Union, one burrito costs $1.50; if you buy more than 10, you get a 10% discount. For example, 5 burritos cost 5 x $1.50 = $7.50; 20 burritos cost (20 x $1.50) * (1-10/100) = $30 * 0.9 = $27. Describe, step-by-step, an algorithm that, given the number of burritos, returns the total price of these burritos.

1) First, multiply $1.50 by the number of burritos. 2) Check if the number of burritos is 10 or smaller. a) If yes, return the number computed on Step 1 as the desired answer b) If no, multiply the number computed on Step 1 by 1 - 10/100 = 0.9.3. For each of the following sequences of symbols, describe which can be valid Java identifiers and which cannot be; if you believe they cannot be, briefly explain why (e.g., "is a reserved word" or "does not start with a letter"):

- WallaceAndGrommit
*valid* - Wallace-Grommit
*not valid: a Java name cannot have - inside* - $1.50
*not valid: a Java name cannot have . inside* - $30
*valid but not recommemded, since it has a $* - double
*not valid: reserved word*

4-5. Burritos again, this time without a discount.
Write a *main* method that asks a student for the number
of burritos, and then computes the total and prints the statement:

For (number) burritos, you pay $(amount).For example, if you ordered 5 burritos, the computer should print:

For 5 burritos, you pay $7.50.

*Reminder:*
to read strings, you can define the input object as follows:

BufferedReader in =to convert the string into a real number, you can use the methodnewBufferedReader(newInputStreamReader(System.in));

Double.parseDouble( )the header of the

publicstaticvoid main(String[] args)throwsIOException{

public static void main(String[] args) throws IOException{ BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); System.out.println("Please enter the number of burritos"); String reads = in.readLine(); int burritos = Integer.parseInt(reads); System.out.println("For "+ buritos+" burritos, you pay $" + 1.50 * (double) burritos+ "."; }6. Due to the success of the new movie "Wallace and Gromit", many Hollywood studios decided to make similar movies about folks and their dogs. Write down a line of code that, given two strings

title = person + " and " + dog;