There are 7 new books and 8 used books on a shelf. (a) What is the ratio of all books to used books?

(b) What is the ratio of new books to all books?


Answer 1

The ratio of all books to used books 15:8

The ratio of new books to all books 7:15

What is ratio?

A ratio indicates how many times one number contains another.


New books =7

used books= 8

total books =8+7=15 books

a) ratio of all books to used books,

= total books: used books

= 15:8

b) ratio of new books to all books,

= new books: all books


Learn more about ratio here:


Answer 2


(a) 15:8

(b) 7:15

Step-by-step explanation:

a: All the books together is 15. The ratio of all books(15) to used books(8) is therefore 15:8

b: As I said above, all the books together is 15. So the ratio of the new books(7) to all books(15) is 7:15

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Two friends take a drive around the city. When they get home, they look at the odometer and their watches, and determine they traveled 54 miles in 72 minutes. What was their average speed in miles per hour?


X miles per hour means that  x miles / 60 minutes 
If they traveled 54 miles / 72 minutes, so:
72 minutes - 60 minutes = 12 minutes 

60 minutes = 1 
12 minutes = 0,2  
1 + 0,2 = 1,2 hour
V = s/t 
v - velocity or speed
s - linear distance traveled 
t - time, so...
 we must divide 54 miles by 1,2 hour = 
Now, as we all know...
Their average speed was 45 miles per hour.
The question asks for the speed in miles per hour, so first thing we have to do is convert 72 minutes into hours by dividing by 60: 1.2 hours.
speed = distance / time
speed = 54 miles / 1.2 hours
speed = 45 miles/hour aka miles per hour aka mph

Jim earns $1,600 per month after taxes. He is working on his budget and has the first three categories finished. Housing $576
Food $272
Transportation $320

Why will he have a problem with the rest of his budget?


He is budgeting too much for transportation. He has used the highest recommended percentages to calculate the amounts for the three categories. He is budgeting too much for housing. He has used the lowest recommended percentages to calculate the amounts for the three categories.

Part A How much voltage must be used to accelerate a proton (radius 1.2 ×10−15m) so that it has sufficient energy to just penetrate a silicon nucleus? A silicon nucleus has a charge of +14e, and its radius is about 3.6 ×10−15m. Assume the potential is that for point charges.



Step-by-step explanation:

Qp = charge on proton = 1.6 x 10-19 C

Qs = charge on silicon = 14 x 1.6 x 10-19 C

rf = final distance from nucleus = ∞

ri = initial distance from nucleus = (3.6 x 10-15 + 1.2 x 10-15 ) = 4.8 x 10-15 m

initial Potential energy is given as

Ui = k Qp Qs / ri = (9 x 109) (1.6 x 10-19 ) (14 x 1.6 x 10-19 ) / (4.8 x 10-15 ) = 6.72 x 10-13 J

final Potential energy is given as

Uf = k Qp Qs / rf = (9 x 109) (1.6 x 10-19 ) (14 x 1.6 x 10-19 ) / (∞) = 0 J

Change in Potential energy = ΔU = Ui - Uf = 6.72 x 10-13 - 0 = 6.72 x 10-13 J

Let the Voltage through which proton is accelerated = V

Energy gained due to potential difference = Qp V

Using conservation of energy

Qp V = 6.72 x 10-13

(1.6 x 10-19 ) V = 6.72 x 10-13

V = 4.2 x 106 volts


In a pnd, there are 56 fish, 12 of them are red. what percent are red


In a pond there are 56 fish.

12 of the fish in the pond are red that means that 44 of the fish are not red.

We can use the fraction to represent the 12 red fish out of all the fish together.

can be reduced by dividing both the numerator and denominator by the greatest common factor of 12 and 56. reduced is .

3 ÷ 14 = 0.21428571428571

0.21428571428571 × 100 = 21.428571428571%

Therefore, 21.428571428571% of the fish are red.


Angle c is an inscribed angle of circle p. angle c measures (3x+4) and arc AB measures (10x). find x


inscribed angle - 3(2)+4=10
arc - 10(2)=20
the Arc is two times the inscribed angle

At the pet shelter,for every 7 dogs there are 5 cats.what is the ratio of dogs to cats? a.5:7


B Because there a 7 dogs and five cats
The answer would be B. When it asks Dogs to Cats. The value for dogs would go first. If it was cats to dogs the cat value would be first

Jake spends 2 hours on each homework assignment and he had 3 assignments each day. Orlando spends 2 hours on each homework assignment and he had 2 homework assignments each day. How much time will Jake and Orlando spend doing homework after 30 days?


Jake: one hundred and eighty hours
Orlando: one hundred and twenty hours

total: three hundred hours
Jake will spend 180 hours on homework assignments after 30 days and Orlando will spend 120 hours on homework assignments after 30 days hope this helps :)  (Jake:2 hours X 30 days = 180hrs) (Orlando:4 hours X 30 days= 120hrs)

John has a choice of two health plans being offered by his employer. The first plan has a $25 co-pay for each doctor visit and has an annual deductible of $2,200. The second plan has no co-pays and has no deductible. The second plan costs $3,000 more in annual premiums than the first. John chooses the first plan and has 10 doctor visits at $200 per visit. Which subsequent events would make this plan more expensive than the second plan? A.
10 more doctor visits at $250 each
a surgery visit costing $1,050
emergency hospitalization costing $30,000
40 more short doctor visits costing $75 each



C. emergency hospitilization costing $30,000

Step-by-step explanation:


the answer is C

Step-by-step explanation:


What geometic figure is made when two planes intersect


a line is formed

correct me if i'm wrong

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