Can anyone help me?

Question

The Sub didn't explain todays math very well =(.. Could anyone help me? Please explain the work..

1. A cost-of-living increase was reported as 2.3%. If the number was determined by an increase of $17 on $750, was it correctly reported?
A. Yes
B. No
C. Both
D. Neither

2. Mary bought highschool pens at 65 cents each, then resold them for 80 cents. What percent profit did she make on the money she spent for the pens?
A. 31.0%
B. 14.5%
C. 27.3%
D. 23.1%

3. In two years the weekly salary increased from $45 to $88. What percent of increase was this to the nearest tenth?
A. 95.6%
B. 90%
C. 88%
D. 93.4%

4. There were 160 boys in the city. The next year there was a 5% increase in the number of boys. Find the new number of boys.
A. 145
B. 168
C. 177
D. 150

Answer 1

I'll answer one of them, which hopefully helps explain how to do all of them.

#2.
p = purchase price = .65
s = sell price = .80
profit = p - s = .15

So you are being asked "what percent profit" on the money "she spent." So she spent .65 per pen, made a .15 profit on that .65:

x * .65 = .15

x = .15 / .65 = .2308 which rounds up to 23.1%.

hope that helps.

Answer 2

1. A cost-of-living increase was reported as 2.3%. If the number was determined by an increase of $17 on $750, was it correctly reported?
A. Yes
B. No
C. Both
D. Neither

17/750=.022666=2.2666%
2.3==.023 .023*750=17.25

rounded to the nearest $ or nearest .1%, it is correct, but not exact.

2. Mary bought highschool pens at 65 cents each, then resold them for 80 cents. What percent profit did she make on the money she spent for the pens?
A. 31.0%
B. 14.5%
C. 27.3%
D. 23.1%
profit=80-60=15 cents
15/65=.2307=23.07% rounded to .1% =23.1% D is correct

3. In two years the weekly salary increased from $45 to $88. What percent of increase was this to the nearest tenth?
A. 95.6%
B. 90%
C. 88%
D. 93.4%
88/45=1.9555
increase is .955555=95.555% rounded to the nearest .1% =95.6% A is correct

4. There were 160 boys in the city. The next year there was a 5% increase in the number of boys. Find the new number of boys.
A. 145
B. 168
C. 177
D. 150

5%=.05 so the increase was .05*160=8 & the new number is 160+8=168 boys B is correct

Answer 3

1) Since 23% of 750 is

.023 * 750 = 17.25

and the increase is probably rounded to the nearest dollar, then $17.00 is right.

2) Start with .65, end with .80, difference = .15, so the % increase is given by

100*.15/.65 = 23.0769, rounds to 23.1

3) Start with $45, end with $88, difference = 43, so the % increase is given by

100 * 43/45 = 95.6

4) The 5% increase is given by

.05 * 160 = 8, so new # = 160 + 8 = 168

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The % figure is 100*rate. If you have the %, say 2.3, the rate to be used is 2.3/100, or .023

It is important to correstly determine the base to be used in the claculation. If you go from .65 to .80, the base is the 'from' figure, or .65

Answer 4

1. a 17/750=.022666
2.d .80-.65=.15/.65=.2307
3.a 88-45=43/45=.9555
4.b 160*5%=8+160=168

Answer 5

1. yes, 17/750*100=2.2666666, when rounded its 2.3%
2.(80-65)/80*100=23.1
3.(88-45)/45*100=95.6
4.160*105/100=168

Answer 6

1. 17*100/750
= 2.26
if rounded up you can say its yes or both

follow this and you shoudl do rest of them

Answer 7

no offense your telling us to do your homework. It would be okay to show us one of the problems but for us to do all of it, thats wrong. You need to pay attention in class.

Answer 8

Do your own homework.