Answer: choice A. 40 liters
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Explanation:
x = number of liters of the 50% alcohol solution
If we have x liters of 50% alcohol, then we have 0.50*x liters of pure alcohol. This is added to 0.90*40 = 36 liters of pure alcohol (from the 90% solution).
So far we have 0.50*x + 36. This expression represents the total amount of pure alcohol. We want a 70% solution, so we want 70% of the total 40+x meaning 0.50*x + 36 is to be set equal to 0.70*(40+x) and we solve for x as shown below
0.50*x + 36 = 0.70*(40+x)
0.50*x + 36 = 0.70*(40)+0.70*(x)
0.50*x + 36 = 28+0.70*x
36 - 28 = 0.70*x - 0.50x
8 = 0.20x
0.20x = 8
x = 8/0.20
x = 40
So that is why the answer is choice A. 40 liters
The chance or chance that the lawn mower will hit a chunk of glass that is already cracked is calculated with the aid of dividing the variety of glasses that are cracked by way of the full quantity of glasses. on this item, the unknown may be calculated through . The solution is, therefore, 0.20.
Opportunity is a measure of the chance of an event to arise. Many occasions cannot be predicted with overall reality. We are able to are expecting only the danger of an event to arise i.e. how likely they're to manifest, using it.
The possibility is the branch of arithmetic regarding numerical descriptions of how in all likelihood an occasion is to arise, or how possibly it's miles that a proposition is actual. The possibility of an occasion various between 0 and 1, where, roughly talking, 0 indicates the impossibility of the event and 1 shows reality.
The probability of an event can be calculated by possibility components via surely dividing the favorable range of effects through the full range of possible outcomes.
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The time it will take to fill the vat if both pipes are left open is = 4.3 hours
<h3>Calculation of time taken to fill vat</h3>
The number of pipes a vat has = 2
The time it takes the inlet pipe to fill the vat = 3hrs
The time it takes the outlet pipe to empty the vat= 10hrs
Therefore, the time it will take to fill the vat if both pipes are left open is;
1/t = 1/3-1/10
1/t = 7/30
Make t the subject of formula,
t = 30/7
t= 4.3 hours
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Angle d is a vertical angle to the 70° angle meaning that angle d is 70°--to confirm it, line EF is 180° and
180- 40-70= 70° (and 70/2 is 35 which is the measurement for angle e and f bc we know that they are equal)
To find a-- we know now that f is 35, bc a and f are vertical angles, that means a is equal to f...
ANSWER- a is 35° and d is 70°
