The value of D should be 4
Step-by-step explanation:
markup amount = 45% of $27
=> 45/100 * $27
=> $12.15
Now,
selling price = $27 + $12.15 => $39.15
Answer:
5/6 books
Step-by-step explanation:
We know that Mark read 2 1/2 books last week. This week, he read a bit more with 3 1/3 books.
To find how many more books he read, we must subtract 2 1/2 from 3 1/3:
3 1/3 - 2 1/2
Let's convert these into improper fractions first:
3 1/3 = (3 * 3 + 1) / 3 = 10/3
2 1/2 = (2 * 2 + 1) / 2 = 5/2
Now, we have:
10/3 - 5/2
In order to subtract these, we must find a common denominator. For 2 and 3, the LCM is 6, so we can use that as our common denominator:
10/3 * 2/2 = 20/6
5/2 * 3/3 = 15/6
Finally, we have:
20/6 - 15/6 = (20 - 15) / 6 = 5/6 books
Answer:
Percentage of balls which are red = 80%.
Step-by-step explanation:
Let the probability of drawing a red ball be x then the probability of drawing a white ball is 1-x.
There are 5C3 = 10 ways of getting 3 reds in 5 draws so the probability of this is 10* x^3 * (1 - x)^2.
The probability of getting 1 red in 5 draws = 5C1 * x (1-x)^4.
The first probability is 32 times the last.
So we have the equation:
10x^3(1 - x)^2 / 5x(1 - x)^4 = 32
2x^2 / (1 - x)^2 = 32
2x^2 = 32(1 -x)^2
2x^2 = 32( 1 - 2x + x^2)
2x^2 = 32 - 64x + 32x^2
30x^2 - 64x + 32 = 0
15x^2 - 32x + 16 = 0
(5x - 4)(3x - 4) = 0
x = 0.8, 1.333...
The probability must be < 1 so x = 0.8 = 80%.
Number of large boxes:
50
Number of small boxes: 65