All categories

3 years ago

A piano has 88 keys. The ratio of white keys to black keys is 13.9. How many black keys does a piano have?

2 answers:

6 0

Black keys=b
white keys=w
b+w=88|·9
w:b=13/9⇒9w=13b
9b+9w=792
13b+9b=792
22b=792|:22
b=36 keys
w=88-36
w=52 keys

lidiya [134]3 years ago

5 0

Answer:

Step-by-step explanation:

Search it up on google

You might be interested in

A rule for creating a pattern is given below.

leonid [27]

Answer:

(any real number, 5)

Step-by-step explanation:

Well given that y=7-2 and that y=5, we do not know the value of x, therefore x could be any real number with y being 5. I'm pretty sure that answered your question. So, a example of an ordered pair that would fit this rule would be say (5,5) or (7,5)

5 0

2 years ago

Thirty students at Eastside High School took the SAT on the same Saturday. Their raw scores are given next. 1,450 1,620 1,800 1,

IRISSAK [1]

Answer:

Number of students who scored atleast 1700 but less Than 2100 = 17

Step-by-step explanation:

Given the data :

1,450 1,620 1,800 1,740 1,650 1,800 2,010 1,780 1,840 1,490 1,620 1,480 2,390 1,640 1,830 1,710 1,900 1,910 1,950 1,820 1,590 2,350 2,260 1,870 1,530 1,950 2,000 1,830 1,980 2,100

Class interval __ Frequency

1400 - 1599 ____ 5

1600 - 1799 ____ 7

1800 - 1999 ____12

2000 - 2199 ___ 3

2200 - 2399 ___ 3

Number of students who scored atleast 1700 but less Than 2100 = 17

8 0

3 years ago

If f(x) =4x +5, what is the value of f(-3)?

Aliun [14]

Answer:

-7

Step-by-step explanation:

7 0

4 years ago

Read 2 more answers

Greatest common factor of 15c^2 and 25n

shtirl [24]

Answer: 5

Step-by-step explanation:

The greatest common factor of 15c^2 and 25n is 5 because if you divid the two numbers by 5, they will both be in their primal state.

15c^2 / 5 = 3c^2

25n / 5 = 5n

6 0

3 years ago

Suppose that Frida selects a ball by first picking one of two boxes at random and then selecting a ball from this box at random.

BaLLatris [955]

Answer:

3/4

Step-by-step explanation:

Given the following :

Number of boxes = 2

First box :

White balls = 3

Blue balls = 2

Second box:

White balls = 4

Blue balls = 1

What is the probability that Frida picked a ball from the first box if she has selected a blue ball?

Probability (P) = (required outcome / Total possible outcomes)

Probability of picking first box : P(F) = 1/2

Probability of not picking second box :P(S) 1/2

Probability of picking blue from first box : P(B | F) = 3/5

Probability of picking blue, but not from first box : P(Blue not from second box) P(B|S) = 1/5

probability that Frida picked a ball from the first box if she has selected a blue ball?

P(F) * P(B|F) ÷ (P(F) * P(B|F)) + (P(S) * P(B|S))

(1/2 * 3/5) ÷ ((1/2 *3/5) + (1/2 * 1/5)

3/10 ÷ (3/10 + 1/10)

3/10 ÷ 4/10

3/10 * 10/4

= 3/4

7 0

3 years ago