1.
8 feet = 96 inches
6 feet = 72 inches
A = LW
A = 96 * 72
A = 6912 square inches
6912 / 36 = ______ tiles
A rectangular floor 8 feet long and 6 feet wide is to be completely covered with tiles. Each tile is a square with a perimeter of 2 feet. What is the least number of such tiles necessary to cover the floor?
A)7
b)12
c)24
d)48
e)192
^I got C
A culture of bacteria initially contained p cells, where p is greater than 100. After one hour, this population decreased by 1/3. In the second and third hours, however, the population increased by 40% and 50%, respectively. At the end of those first three hours, what was the population of the culture?
A)1.3p
B)1.4p
C)1.5p
D)1.6p
^I do not know
A jar contains only red, white, and blue marbles. It contains twice as many red marbles as white marbles and three times as many white marbles as blue marbles. If a marble is chosen at random, what is the probability that is NOT red?
A)1/5
B)2/5
C)3/5
D)4/5
4 answers
1) (B)
Area of the floor = 6*8 = 48 square units
Area of each tile = 2*2 = 4 square units
Tiles needed = 48/4 = 12
The answer is 12
2) (B)
Let's take the initial number of cells as p.
After one hour -> Decrease of 1/3 -> (2/3)p remains
After another hour -> Increase of 40% -> New amount is 140/100 times the old amount -> New amount is (2/3)p * (140/100) = (14/15)p
After another hour -> Increase of 50% -> New amount is 150/100 times the old amount -> New amount is (14/15)p*(150/100) = (7/5)p = 1.4p
The answer is 1.4p
3) (B)
Blue marbles = x
White marbles = 3x
Red marbles = 2(3x) = 6x
Total = 10x
Probability of not being red = (3x + x)/10x
= 4x/10x
4/10 = 2/5
Area of the floor = 6*8 = 48 square units
Area of each tile = 2*2 = 4 square units
Tiles needed = 48/4 = 12
The answer is 12
2) (B)
Let's take the initial number of cells as p.
After one hour -> Decrease of 1/3 -> (2/3)p remains
After another hour -> Increase of 40% -> New amount is 140/100 times the old amount -> New amount is (2/3)p * (140/100) = (14/15)p
After another hour -> Increase of 50% -> New amount is 150/100 times the old amount -> New amount is (14/15)p*(150/100) = (7/5)p = 1.4p
The answer is 1.4p
3) (B)
Blue marbles = x
White marbles = 3x
Red marbles = 2(3x) = 6x
Total = 10x
Probability of not being red = (3x + x)/10x
= 4x/10x
4/10 = 2/5
2) After the first hour, p decreased by 1/3 of p, so it became p-p/3=2p/3.
Then, when it increased by 40% it became 2p/3*1.4
2p/3*14/10
2p/3*7/5
14p/15
Finally, it increased by 50%
14p/15*1.5
(14p*1.5)/15
21p/15
7p/5
in decimal form this is 1.4p, which is B
3) let us call the number of blue marbles "b". then the number of white marbles is thrice as much, or 3b. The number of red marbles is twice the number of white marbles, or 2*3b=6b
Blue: b
White: 3b
Red: 6b
The total amount is 10b
the amount that is not red is b+3b=4b
4b/10b=2/5, choice B
Then, when it increased by 40% it became 2p/3*1.4
2p/3*14/10
2p/3*7/5
14p/15
Finally, it increased by 50%
14p/15*1.5
(14p*1.5)/15
21p/15
7p/5
in decimal form this is 1.4p, which is B
3) let us call the number of blue marbles "b". then the number of white marbles is thrice as much, or 3b. The number of red marbles is twice the number of white marbles, or 2*3b=6b
Blue: b
White: 3b
Red: 6b
The total amount is 10b
the amount that is not red is b+3b=4b
4b/10b=2/5, choice B
a square tile with a 2 ft perimeter is 1/2 ft on each side
you can fit 16 tiles on the 8 ft dimension, and 12 on the 6 ft dimension
16 * 12 = ?
2/3 * 1.4 * 1.5 = ?
w = 3 b
r = 2 w = 6b
b + 3b + 6b = 10b
fraction r = 6b / 10b = 6/10 = 3/5
so, not r is ... 1 - 3/5
1 out of 3 for jerkthug
you can fit 16 tiles on the 8 ft dimension, and 12 on the 6 ft dimension
16 * 12 = ?
2/3 * 1.4 * 1.5 = ?
w = 3 b
r = 2 w = 6b
b + 3b + 6b = 10b
fraction r = 6b / 10b = 6/10 = 3/5
so, not r is ... 1 - 3/5
1 out of 3 for jerkthug
3 answers