1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
solmaris [256]
2 years ago
15

If 30% of John's photographs were perfect, but 210 photographs were not perfect, then how many photographs were there in all?

Mathematics
1 answer:
loris [4]2 years ago
8 0
If 30% were perfect, 70% were not perfect.  So we know that 70% of the total number of photographs is 210.

p(70/100)=210  multiply both sides by 100

70p=21000  divide both sides by 70

p=300

So there are 300 photographs in all.
You might be interested in
Please explain how to do this, I'm using all my points<br><br>A. 40 L<br>B. 80 L<br>C. 4 L <br>D. 8L
exis [7]

Answer: choice A. 40 liters

====================================

Explanation:

x = number of liters of the 50% alcohol solution

If we have x liters of 50% alcohol, then we have 0.50*x liters of pure alcohol. This is added to 0.90*40 = 36 liters of pure alcohol (from the 90% solution).

So far we have 0.50*x + 36. This expression represents the total amount of pure alcohol. We want a 70% solution, so we want 70% of the total 40+x meaning 0.50*x + 36 is to be set equal to 0.70*(40+x) and we solve for x as shown below

0.50*x + 36 = 0.70*(40+x)

0.50*x + 36 = 0.70*(40)+0.70*(x)

0.50*x + 36 = 28+0.70*x

36 - 28 = 0.70*x - 0.50x

8 = 0.20x

0.20x = 8

x = 8/0.20

x = 40

So that is why the answer is choice A. 40 liters

6 0
2 years ago
Needed Right now Worth 50 points
zimovet [89]

a = The cost of the pizza.

b = The cost of the pizza and sales tax.

f(a) = The cost of the pizza.

g(b) = The cost of the pizza and sales tax.

g(f(a)) = The cost of the pizza, sales tax, and delivery fee

5 0
2 years ago
Please help me asnwer this question
KATRIN_1 [288]
It would take 55 Minutes
8 0
3 years ago
The relative frequency distribution of the number of phobias reported by a hypothetical sample of 500 college students is given
goldenfox [79]

Answer:

a. 0.48

b. 0.14

c. 0.47

Step-by-step explanation:

Data provided in the question

0 - 2        0.48

3 - 5        0.26

6 - 8        0.12

9- 11        0.09

12- 14       0.05

Based on the above information

a. The probability for fewer than three phobias is

= P( x < 3)

= 0.48

b.  The probability for more than eight phobias is

= P( x >8)

= 0.09 + 0.05  

= 0.14

c. Probability between 3 and 11 phobias is  

= P(3 < x < 11)

= 0.26 + 0.12  + 0.09

= 0.47

3 0
3 years ago
PLEASE HELP ASAP!!
Elza [17]

Answer:

The parabolic equation does not intersect the linear equation.

Explanation:

Given equation's:

  • y = x² − 5x + 9
  • y = -2x

To solve , use substitution method by inserting 2nd equation into 1st

\sf y = x^2 - 5x + 9

when substituted y = -2x

\sf -2x = x^2 - 5x + 9

collect terms

\sf  x^2 - 5x+ 2x + 9=0

simplify

\sf  x^2 - 3x + 9=0

Find discriminant:

\sf b^2 - 4ac

\sf (-3)^2 - 4(1)(9)

\sf -27

As the discriminant is negative, it tell us that they both does not intersect each other.

7 0
1 year ago
Other questions:
  • Which equation represents a line that passes through 4 6) and is parallel to the line whose equation is 3x - 4y= 6
    13·1 answer
  • Solve the equation using a method other than factoring. Show all your work.<br> x² - 7x + 3 = 0
    14·1 answer
  • I need help for this multiply choice geometry problem
    10·1 answer
  • there are seven books on the floor. The number of books on the shelf is two more than three times the number of books on the flo
    5·1 answer
  • Write the following expression. The quantity 81 minus 5k, squared
    12·1 answer
  • Remy drinks 214 cups of water every 145 hours.
    13·2 answers
  • Is 1.2 greater or less than 1.35
    10·1 answer
  • What is y = 1/3x + 8 2/3 in point-slope form?
    11·1 answer
  • Qual o valor numérico do polinômio 3x+2y para x=3 e y=1?
    10·1 answer
  • Pleaseee answer this!!!!
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!