IS 3. 3y-2x
loss
Percentage loss =
X 100%.
selling price
is
Choose the correct answer from the given four alternaives.
In a school, 58% of the total numbers of students are boys. If the
number of girls is 840, how many students are there in the class?
a. 2000
b. 1800
C. 1500
d. 2100
Birr 300 is invested at 6% simple interest per annum. How long will it
take for the interest to amonut Birr 180?
a. 12 years
b. 10 years
c. 8 years
d. 24 years
The decimal form of 672.937% is
a.6.72937
d. 6729.37
b. 67.2937
c. 672.937
9. The simple interest on Birr 400 invested for 4 months was Birr 12.
What is the annual (yearly) rate of interest?
d) 9%
a. 36%
b. 4.8 %
c. 7%

1. a. 2,000

2. b. 10 years

3. a. 6.72937

4. d. 9%

Step-by-step explanation:

1. If 58% are boys, the percentage of girls is:

= 100 - 58

= 42%

That means 840 is 42% of the students in class. The students in class are therefore:

= 840 / 42%

= 2,000 students

2. If Birr 300 is invested at 6% per year, the amount in interest it earns per year is:

= 300 * 6%

= Birr 18

To get to Birr 180, it would take:

= 180/18

= 10 years

3. When a number is in percentage that means that it is a fraction with the denominator being 100. The number is decimal will therefore be it divided by 100:

= 672.937/100

= 6.72937

4. The investment accrued Birr 12 out of Birr 400 in 4 months. This means that it increased by:

= 12/400

= 3%

A year can be divided into three by 4 months. This means that the yearly rate is therefore:

= 3% * 3

= 9%

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: