All categories

3 years ago

2020-21

Mathematics

1 answer:

Dvinal [7]3 years ago

5 0

Answer: Brain paid $ 45.5 for the jacket.

Step-by-step explanation:

Given: Original price of jacket = $ 65

Discount -= 30%

Price after discount = Original price - 30% of Original price

= 65 - 30% of 65

= 65 - (0.3) x 65 [30% = 0.3]

= (65) (1-0.3 ) [Taking 65 common]

= (65)(0.7)

= $ 45.5

Hence, Brain paid $ 45.5 for the jacket.

You might be interested in

Each side of a square is increasing at a rate of 5 cm/s. At what rate (in cm2/s) is the area of the square increasing when the a

Naddika [18.5K]

The area of the square increasing at 30 $\frac{cm^{2} }{sec}$

The rate of change function is defined as the rate at which one quantity is changing with respect to another quantity. In simple terms, in the rate of change, the amount of change in one item is divided by the corresponding amount of change in another

Let the side of a square be x.

So,

Area of square = $x^{2}$

A = $x^{2}$

Differentiating with respect to time we get,

dA/dt = 2x dx/dt

When area = 9 $cm^{2}$ the side becomes 3 cm

At x = 3cm and dx/dt = 5 cm/s (Given)

dA/dt = 2.3.5 = 30 $\frac{cm^{2} }{sec}$

Thus the area of the square increasing at 30 $\frac{cm^{2} }{sec}$

Learn more about rate of change here :

brainly.com/question/12786410

#SPJ4

4 0

2 years ago

I NeED HeLP ASAP with this question

Softa [21]

It is Choice C. Hope this helped!

5 0

3 years ago

. A box in a certain supply room contains four 40-W lightbulbs, five 60-W bulbs, and six 75-W bulbs. Suppose that three bulbs ar

yaroslaw [1]

Answer:

a) 59.34%

b) 44.82%

c) 26.37%

d) 4.19%

Step-by-step explanation:

(a)

There are in total 4+5+6 = 15 bulbs. If we want to select 3 randomly there are K ways of doing this, where K is the combination of 15 elements taken 3 at a time

$K=\binom{15}{3}=\frac{15!}{3!(15-3)!}=\frac{15!}{3!12!}=\frac{15.14.13}{6}=455$

As there are 9 non 75-W bulbs, by the fundamental rule of counting, there are 6*5*9 = 270 ways of selecting 3 bulbs with exactly two 75-W bulbs.

So, the probability of selecting exactly 2 bulbs of 75 W is

$\frac{270}{455}=0.5934=59.34\%$

(b)

The probability of selecting three 40-W bulbs is

$\frac{4*3*2}{455}=0.0527=5.27\%$

The probability of selecting three 60-W bulbs is

$\frac{5*4*3}{455}=0.1318=13.18\%$

The probability of selecting three 75-W bulbs is

$\frac{6*5*4}{455}=0.2637=26.37\%$

Since the events are disjoint, the probability of taking 3 bulbs of the same kind is the sum 0.0527+0.1318+0.2637 = 0.4482 = 44.82%

(c)

There are 6*5*4 ways of selecting one bulb of each type, so the probability of selecting 3 bulbs of each type is

$\frac{6*5*4}{455}=0.2637=26.37\%$

(d)

The probability that it is necessary to examine at least six bulbs until a 75-W bulb is found, supposing there is no replacement, is the same as the probability of taking 5 bulbs one after another without replacement and none of them is 75-W.

As there are 15 bulbs and 9 of them are not 75-W, the probability a non 75-W bulb is $\frac{9}{15}=0.6$

Since there are no replacement, the probability of taking a second non 75-W bulb is now $\frac{8}{14}=0.5714$

Following this procedure 5 times, we find the probabilities

$\frac{9}{15},\frac{8}{14},\frac{7}{13},\frac{6}{12},\frac{5}{11}$

which are

0.6, 0.5714, 0.5384, 0.5, 0.4545

As the events are independent, the probability of choosing 5 non 75-W bulbs is the product

0.6*0.5714*0.5384*0.5*0.4545 = 0.0419 = 4.19%

3 0

3 years ago

Solve. 14/n+7=10/n-4 N=5.25 N=3.5 N=31.5 N=30

Ilya [14]

Answer:

n=31.5

Step-by-step explanation:

The given question is:

$\frac{14}{n+7}=\frac{10}{n-4}$

Cross multiply to get:

$14(n-4)=10(n+7)$

Expand the parenthesis:

$14n-56=10n+70$

Group similar terms:

$14n-10n=70+56$

Combine the like terms

$4n=126$

Divide both sides by 4

$n=\frac{126}{4}$

n=31.5

5 0

3 years ago

HELP PLEASE

Fantom [35]

Answer:

Option C

Step-by-step explanation:

You forgot to attach the expression that models the cost of the camping trip during the three days. However, by analyzing the units, the answer can be reached.

The total cost has to be in units of $.

There are two types of costs in the problem:

Those that depend on the number of days ($/day )

Those that depend on the number of students and the number of days ($/(student * day))

If there are 3 days of camping and b students, then you have to multiply the costs that depend on the days by the number of days (3), and the costs that depend on the number of students you have to multiply them by 'b'

So, if the costs that must be multiplied by 'b' are only those that depend on the number of students, the coefficient of b must be:

3 days (Cost of training + Cost of food Miscellaneous expenses :).

Therefore the correct answer is option C:

C. It is the total cost of 3 days per student of Mr. Brown, with training, food and miscellaneous expenses.

The expression that represents the total expense should have a formula similar to this:

$y = (3 days) *([\frac{20.dollars}{(day * student)} + \frac{30.dollars}{(student * day)} + \frac{50.dollars}{(student * day)}] b + \frac{200}{day}) + 1050.dollars$

y = 3 ($ 100b + $ 200) + $ 1050

3 0

3 years ago

Read 2 more answers