Exactly 80 liters of 20% are needed.
Let quantity of 20% alcohol solution be added : x liters
Here is the work:
> x*20% + 40 * 50% = (x+40) * 30%
> x*0.2 + 40*0.5 = (x+40)*0.3 ..(converting percentages into decimal)
> 0.2x + 20 = 0.3x + 12
> 20-12 = 0.3x - 0.2x (Rearranging similar terms)
> 8 = 0.1 x
Hence x = 8/0.1
Ans 80 Litres
Using previously given equation, the estimate of the GPA of a student who studies for 15 hours a week is; 3.1
<h3>How to predict an equation?</h3>
The equation here is probably a "best fit" equation based upon given data which is GPA versus the number of hours of study per week.
Now, the equation of best fit is given as;
y = 0.149x + 0.89
Thus, if the number of study hours of interest is 15, then the GPA is;
GPA = 0.149(15) + 0.89
GPA = 3.1
Read more about equations at; brainly.com/question/1214333
#SPJ1
There are different kinds of Heat Transfer. Conduction is the transfer of Thermal energy from one object to another through the movement of Molecules Heat flows from one molecule to another because the particles are in Direct contact with one another.
Conduction is known to be described as the transfer of heat between substances that are said to be in direct contact with each other.
The more the increase in the conductor, the more fast the heat will be transferred. Metal are known to be a good conduction of heat.
Conduction is known to often take place when a substance is heated and as such particles will have a lot of energy, and vibrate more.
Learn more about Conduction from
brainly.com/question/893656
The angle of the triangle ABC from smallest to largest are approximately 22°, 27° and 131°.
The sides of the triangle are as follows;
AB = 20
BC = 12
AC = 10
Let's find ∠A using cosine rule,
a² = b² + c² - 2bc cos A
cos A = b² + c² - a² / 2bc
Therefore,
cos A = 10² + 20² - 12² / 2 × 10 × 20
cos A = 100 + 400 - 144 / 400
cos A = 356 / 400
cos A = 0.89
A = cos⁻¹ 0.89
A = 27.1267531173
∠A ≈ 27°
Using sine rule let's find ∠B
12 / sin 27 = 10 / sin B
cross multiply
12 sin B = 10 sin 27
sin B = 10 sin 27 / 12
sin B = 10 × 0.45399049974 / 12
sin B = 4.5399049974 / 12
B = sin⁻¹ 0.37832541645
B = 22.2299936087
∠B = 22°
Using sum of triangle theorem let's find ∠C
∠C = 180 - 27 - 22
∠C = 131°
The angles from smallest to largest are approximately 22°, 27° and 131°.
learn more on triangle here: brainly.com/question/12913110?referrer=searchResults
