Answer:

Step-by-step explanation:
As given
if n erasers have a weight of 80 grams .
I.e
n erasera = 80 grams.
1 erasers weight .

Now find out the weight of the 50 erasers.

Simplify the above


Answer:
- temperature is decreasing as time passes
- x-axis
- hot drink temperature (°C)
Step-by-step explanation:
1. Each value of temperature is lower than the one previous, so we can say the temperature is decreasing. We also notice that the rate of decrease is getting smaller, possibly because the temperature is approaching a horizontal asymptote.
__
2. The horizontal axis, where temperature is plotted, is conventionally called the x-axis.
__
3. The label on the vertical axis is "temperature" and the graph title is "cooling a hot drink ...", so we presume the dependent variable is the temperature of a hot drink.
Answer:
- 33 1/3 liters of 30%
- 16 2/3 liters of 45%
Step-by-step explanation:
Let x represent the liters of 45% solution needed. Then the amount of HCl in the mix is ...
0.45x +0.30(50 -x) = 0.35(50)
0.15x = 0.05(50) . . . . . simplify, subtract 0.30(50)
x = (0.05/0.15)(50) = 50/3 = 16 2/3 . . . liters of 45% HCl
33 1/3 liters of 30% and 16 2/3 liters of 45% HCl are needed.
_____
<em>Comment on the solution</em>
You may notice that the general solution to a mixture problem of this sort is that the fraction of the mix that is the highest contributor is ...
(mix % - low %) / (high % - low %) = (.35 -.30) / (.45 -.30) = .05/.15 = 1/3