Q1. Eight different letters of the alphabet are given. Words of 4 letters are to be formed using only the given letters. Find the number of different words that can be formed if
(a) repetition of letters is not allowed,
(b) repetition of letters is allowed,
(c) at least one letter is repeated.

Q2. 36. (a) How many 3-digit numbers are there?
(b) How many 3-digit numbers are there such that at least one of their digits is 7?

Q3. The results of 8 matches (Win, Lose or Draw) are to be predicted. Find the number of different forecasts that contain exactly 6 correct results.

Hello, I need help with part Q1(c), Q2(b) and Q3. Could you explain them please. The answer is 2416 for c and 252 for b and 112 for Q3. Thanks in advance.

when functions are first introduced, you will probably have some simplistic "functions" and relations to deal with, usually being just sets of points. these won't be terribly useful or interesting functions and relations, but your text wants you to get the idea of what the domain and range of a function are. small sets of points are generally the simplest sorts of relations, so your book starts with those.

step-by-step explanation:

state the domain and range of the following relation. is the relation a function?

{(2, –3), (4, 6), (3, –1), (6, 6), (2, 3)}

the above list of points, being a relationship between certain x's and certain y's, is a relation. the domain is all the x-values, and the range is all the y-values. to give the domain and the range, i just list the values without duplication:

domain: {2, 3, 4, 6}

range: {–3, –1, 3, 6}

(it is customary to list these values in numerical order, but it is not required. sets are called "unordered lists", so you can list the numbers in any order you feel like. just don't duplicate: technically, repetitions are okay in sets, but most instructors would count off for this.)

while the given set does indeed represent a relation (because x's and y's are being related to each other), the set they gave me contains two points with the same x-value: (2, –3) and (2, 3). since x = 2 gives me two possible destinations (that is, two possible y-values), then this relation is not a function.

note that all i had to do to check whether the relation was a function was to look for duplicate x-values. if you find any duplicate x-values, then the different y-values mean that you do not have a function. remember: for a relation to be a function, each x-value has to go to one, and only one, y-value.

state the domain and range of the following relation. is the relation a function?

{(–3, 5), (–2, 5), (–1, 5), (0, 5), (1, 5), (2, 5)}

i'll just list the x-values for the domain and the y-values for the range:

answer: an 8-foot rope is tied from the top of a pole to a

stake in the ground, as shown in the diagram

below

step-by-step explanation:

h= 12 inches

step-by-step explanation: