1. The price of a book decreased from #25 to #20. By how many percent did the price decrease?

a. 5
b. 10
c. 20
d. 25

2. After taking several practice tests, Brian improved the results of his GRE test by 30%. Given that the first time he took the test Brian had answered 150 questions correctly, how many correct answers did he answer in the second test?

a. 105
b. 120
c. 180
d. 195

3. A number is increased by 2 and then multiplied by 3. The result is 24. What is this number?

a. 4
b. 6
c. 8
d. 10

4. My father’s age divided by 5 is equal to my brother’s age divided by 3. My brother is 3 years older than me. My father’s age is 3 less than 2 times my age. How old is my father?

a. 34
b. 45
c. 56
d. 61

5. (x – 2) / 4 – (3x + 5) / 7 = – 3, x = ?

a. 6
b. 7
c. 10
d. 13

(1) C

(2) D

(3) B

(4) B

(5) C

Step-by-step explanation:

(1) % decrease = change in price/initial price × 100 = (25 -20)/25 × 100 = 5/25 × 100 = 20

(2) Number of correct answers he answered in the second test = 150 + (30/100 × 150) = 150 + 45 = 195

(3) Let the number be y

3(y + 2) = 24

y + 2 = 24/3 = 8

y + 2 = 8

y = 8 - 2 = 6

(4) Let my father's age be f, my brother's age be b and my age be m

From the first statement

f/5 = b/3 eqn (1)

From the second statement

b = m + 3 eqn (2)

From the third statement

f = 2m - 3 eqn (3)

Substitute the expression of b and f in eqn 2 & 3 into eqn 1

(2m - 3)/5 = (m + 3)/3

3(2m - 3) = 5(m + 3)

6m - 9 = 5m + 15

6m - 5m = 15 + 9

m = 24

Substitute the value of m into eqn 3

f = 2m - 3 = 2(24) - 3 = 48 - 3 = 45

(5) (x - 2)/4 - (3x + 5)/7 = -3

The LCM of 4 and 7 is 28

Multiply each term in the equation by 28

7(x - 2) -4(3x + 5) = -3(28)

7x - 14 - 12x - 20 = -84

-5x - 34 = -84

-5x = -84 + 34

-5x = -50

x = -50/-5 = 10

median is the value separating the higher half of a data sample, a population or probablity distribution from the lower half.

step-by-step explanation:

say you have 3,8,7,3,1,9,8 order them from lowest to highest

if orderd it would be 1,3,3,7,8,8,9 now you take away from the lowest and the highest until you end up in the middle.

so you would remove the 1 and 9 leaving you with 5 digits remaining

when you've reached the middle that would be your answer so in this case the answer is 7

if there were two numbers left say 7 and 5 you'd and them together so 12 then divide by 2 witch would equal 6 so the answer would be 6

good luck on that project hoped i you at all

the answer is; biodiversity resulting from few ancestors

adaptive radiation occurs when a population is subjected to a large natural environment with spatial ecological variations. the parts of the population in the different ecologies begin to adapt to their local environments. due to non-random mating across the large populations, this causes the different populations from the large population to speciate within their local environments. they, therefore, diverge to different species sharing a common ancestor.