Answer:
10 tapes and 6 Cds
Step-by-step explanation:
As tapes sell for $10 and CD sell for $15, let t be the number of tapes bought and c the number of cds, we can write an equation for the expenditure in the form:
10c + 16t = expenditure
We also n=know she spent 220, so:
10c + 16t = 220
As she bought 16 items, the sum of CD and tapes must be equal to 16. So:
c + t = 16
If we take this last equation and subtract t in both sides:
c = 16 - t
We got the number of CD depending on the number of tapes. We can replace this in the first equation to get t:
10 [16 - t] + 16t = 220
160 - 10 t +16t = 220
160 + 6t = 220
If we subtract 160 in both sides
6t = 220 - 160
6t = 60
Dividing both by 6:
t = 60/6 = 10
So, she purchased 10 tapes. As in total she purchased 16 items she must have purchased 6 cds.
Solution: She purchased 10 tapes and 6 CDs
Answer:
A
Step-by-step explanation:
because it makes more sense
Answer:
(60.382 ; 83.998)
Step-by-step explanation:
The confidence interval is given as :
Mean ± Margin of error
Mean = 72.19
The margin of error is : Tcritical * s/√n
n = 13 ; s = 15.88
Tcritical at 98%, df = 13-1 = 12 = 2.681
Margin of Error = 2.681 * 15.88/√13 = 11.808
Confidence interval = 72.19 ± 11.808
(60.382 ; 83.998)
Answer:
3125
Step-by-step explanation:
first, find the unit rate.
2500/4=625
625= amount of oxygen needed to supply a family of one(or just one single person)
625*5=3125
***with these problems, always try to find the unit rate first which is the amount of something per one unit. it'll be helpful to solve the questions following it.
You would need this symbol: <
