Chucks age=C
Dave’s age=x
C=x-3
Answer:
180 coins
Explanation:
N = number of nickels (no nickels spent)
D = number of dimes initially saved
D' = number of dimes left after spending
1) N = D + 43
2) D' = D - 17
3) N = 2*D' = 2*(D - 17)
Set equations 1) and 3) equal to each other and solve for D:
D + 43 = 2*(D - 17)
D + 43 = 2*D - 34
D = 43 + 34 = 77
N = D + 43 = 77 + 43 = 120 nickels left
D' = D - 17 = 77 - 17 = 60 dimes left
Total coins left = 120 + 60 = 180 coins (I hope this is not too confusing for you)
22.5 miles
You would create a proportion based on the given information, then cross multiply and solve for the number of miles 1 gallon of gas can go.
The distribution of the number of occurrences of the letter t on the pages of a book is found to be a normal distribution with a mean of 44 and a standard deviation of 18. If there are 500 pages in the book, which sentence most closely summarizes the data?
A. The letter t occurs less than 26 times on approximately 170 of these pages.
B. The letter t occurs less than 26 times on approximately 15 of these pages.
C. The letter t occurs more than 26 times on approximately 420 of these pages.
D. The letter t occurs more than 26 times on approximately 80 of these pages.
.Answer:
<span>mean = 44 </span>
<span>sd = 18 </span>
<span>that means that "26" is 1 s.d. down, or at the 16th %ile </span>
<span>so, there is a .16 chance that "t" will occur less than 26 times on any single page. </span>
<span>consequently, there is a .84 chance that it will occur more than 26 times on any single page. </span>
<span>Using that information, and knowing that 16% of 500 is 80, and 84% of 500 is 420, can you see where "C" is correct? </span>
