The store has sold 90 notebooks which is 20% of all the notebooks they had how many notebooks did the store have at first

How do you solve 9 tenths minus 13 fiftenths

Elena L [17]

Answer:

0.04

Step-by-step explanation:

1. 9/10 = 0.9 and 13/15 = 0.86

2. Subtract 0.9 and 0.86

3. You should end up with 0.04

Remember when a number goes like 0.86666666666 to use 0.86 or if it has 0.86666666667 to use 0.87 because you would be simplifying it.

4 0

3 years ago

A box contains 5 red balls, 6 white balls and 9 black balls. Two balls are drawn at

valina [46]

Answer:

$P(Same)=\frac{61}{190}$

Step-by-step explanation:

Given

$Red = 5$

$White = 6$

$Black = 9$

Required

The probability of selecting 2 same colors when the first is not replaced

The total number of ball is:

$Total = 5 + 6 + 9$

$Total = 20$

This is calculated as:

$P(Same)=P(Red\ and\ Red) + P(White\ and\ White) + P(Black\ and\ Black)$

So, we have:

$P(Same)=\frac{n(Red)}{Total} * \frac{n(Red) - 1}{Total - 1} + \frac{n(White)}{Total} * \frac{n(White) - 1}{Total - 1} + \frac{n(Black)}{Total} * \frac{n(Black) - 1}{Total - 1}$

<em>Note that: 1 is subtracted because it is a probability without replacement</em>

$P(Same)=\frac{5}{20} * \frac{5 - 1}{20- 1} + \frac{6}{20} * \frac{6 - 1}{20- 1} + \frac{9}{20} * \frac{9- 1}{20- 1}$

$P(Same)=\frac{5}{20} * \frac{4}{19} + \frac{6}{20} * \frac{5}{19} + \frac{9}{20} * \frac{8}{19}$

$P(Same)=\frac{20}{380} + \frac{30}{380} + \frac{72}{380}$

$P(Same)=\frac{20+30+72}{380}$

$P(Same)=\frac{122}{380}$

$P(Same)=\frac{61}{190}$

4 0

3 years ago

please explain the steps that are used to solve this??? Given:2(10 -13x)+9=-34x+60 Step 1:20-26x=-34x+60 Step 2:-26x=-34x+40 Ste

solmaris [256]

You left out the 9 in the whole equation. The 1st step you had right you just forgot to put +9. 2nd step you are combining the like terms and get 11-26x=-34x+40. Step 3: you are trying to isolate the x on one of the sides. You need to switch the 11 over to the 40 and get 29. Move -34x over to -26x and get 8x. Step 4 all you are doing in dividing 8 from both sides and get 5.

4 0

3 years ago

How do you do this trig problem.

loris [4]

Consider a right triangle in which one of the angles $\theta$ satisfies

$\sin\theta=\dfrac35\implies\theta=\sin^{-1}\dfrac35$

That is, the side opposite $\theta$ occurs in a ratio of 3 to 5 with the hypotenuse. The side adjacent to $\theta$ then occurs in a ratio of 4 to 5 with the hypotenuse. In other words,

$\cos\theta=\dfrac45$