So she reads for 5 hours every day for 15 days, how many hours is that? well is just 5*15, or 75 hours.
so, she reads 900 pages in 75 hours, how many pages does she do in 1 hour?
0.7n + 0.8n = 2.1
1.5n = 2.1 (add like terms(0.7+0.8=1.5))
n=2.1/1.5 (get en on its own)
n=1.40
Answer:
<h3>
38, 39 </h3>
Step-by-step explanation:
The difference between two consecutive integers is 1
So if
x - the smaller number
then
x+1 - the larger number
x + x+1 = 77
-1 -1
2x = 76
÷2 ÷2
x = 38
x+1 = 38+1 = 39
Answer:
Grade A: 
Grade B: 
Grade C: 
Grade D: 
Step-by-step explanation:
Problems of normally distributed samples can be solved using the Z score table.
The Z score of a measure represents how many standard deviations it is above or below the mean of all the measures.
Each Z score has a pvalue. This represents the percentile of the measure.
In this problem, we have that:
The upper 16% of the class get A grades. The upper 16% has a pvalue of at least 100% = 16% = 84% = 0.84. This is
.
The middle 34% of the class get B grades. The middle 34% has a pvalue of at least 84%-35% = 50% = 0.5 and at most 0.84. This is
.
Those between a pvalue of 0.5-0.34 = 0.16 and 0.5 get get grade C.
has a pvalue of 0.16. So a grade C is in the interval
.
Those with Z lesser than -1 get grades D and F