A fair dice is rolled.

A country's population in 1993 was 204 million. In 2000 it was 208 million. Estimate the population in 2015 using the exponentia

Luba_88 [7]

Answer:

217

Step-by-step explanation:

3 0

3 years ago

41. Assuming that a man can complete the work alone in x days, his work in four days would be: a) b) X X C d) 4x x 42. If a man

Schach [20]

Percentage and ratio word problems require understanding of the relationship between variables from which the question is formed

The options that give the correct values of the duration of the work are;

$41. \ c) \ \dfrac{4}{x}$

$42. \ d) \ \dfrac{4}{x} + \dfrac{6}{y} = \dfrac{1}{5}$

43. a) 35 days

44. c) 21·a + 28·b = 1

45. c) (42, 56)

Reasons:

41. Number of days it takes a man to complete the work alone = x days

Therefore;

$The \ work \ done \ by \ the \ man \ in \ one \ day = \dfrac{1}{x}$

$The \ work \ done \ in \ four \ days \ by\ the \ man = 4 \times \dfrac{1}{x} = \dfrac{4}{x}$

The correct option is $c) \ \dfrac{4}{x}$

42. Number of days it takes a man to complete the work alone = x days

$Work \ done \ by \ a\ man \ in \ one \ day = \dfrac{1}{x}$

$Work \ done \ by \ four \ men \ in \ one \ day = \dfrac{4}{x}$

Number of days it takes a boy to complete the work alone = y days

$Work \ done \ by \ a \ boy \ in \ one \ day = \dfrac{1}{x}$

$Work \ done \ by \ six \ boys \ in \ one \ day = \dfrac{6}{y}$

4 men and 6 boys work for 5 days to complete the work

Therefore, work done by 4 men and 6 boys in 1 day is therefore;

$\dfrac{4}{x} + \dfrac{6}{y} = \dfrac{1}{5}$

The correct option is therefore;

$d) \ \dfrac{4}{x} + \dfrac{6}{y} = \dfrac{1}{5}$

43. As per the case study, we have;

Case 1

$\dfrac{4}{x} + \dfrac{6}{y} = \dfrac{1}{5}$

Which gives;

$\dfrac{6\cdot x + 4\cdot y}{y \cdot x} = \dfrac{1}{5}$

30·x + 20·y = y·x

Case 2

$\dfrac{3}{x} + \dfrac{4}{y} = \dfrac{1}{7}$

Which gives;

$\dfrac{4\cdot x + 3\cdot y}{y \cdot x} = \dfrac{1}{7}$

28·x + 21·y = y·x

Therefore;

30·x + 20·y = 28·x + 21·y

∴ 2·x = y

Plugging in the value of y = 2·x, in Case 1 gives;

$\dfrac{4}{x} + \dfrac{6}{2 \cdot x} = \dfrac{1}{5}$

$\dfrac{2 \times 4 + 6}{2 \times x} = \dfrac{14}{2 \times x} =\dfrac{7}{x} = \dfrac{1}{5}$

7 × 5 = x

x = 7 × 5 = 35

The number of days, x, it takes a man to complete the work alone, is given by option; a) 35 days

44. For the equation $\dfrac{3}{x} + \dfrac{4}{y} = \dfrac{1}{7}$ , if $a = \dfrac{1}{x}$ , and $b = \dfrac{1}{y}$ , we have;

$3 \cdot a+ 4\cdot y = \dfrac{1}{7}$

21·a + 28·y = 1

The correct option is option C. 21·a + 28·b = 1

45. A solution to the equation $\dfrac{3}{x} + \dfrac{4}{y} = \dfrac{1}{7}$ , is given by the values of x, and y, that gives;

$\dfrac{1}{14} + \dfrac{1}{14} = \dfrac{1}{7}$

We have;

3 × 14 = 42

4 × 14 = 56

Therefore, a solution to the equation is (42, 56)

The correct option is $c) \ \underline{ (42, \ 56)}$

Learn more here:

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3 0

2 years ago

Can anyone help me with this?? i dont know how to get letter h.

MAVERICK [17]

This can be solved by using the 30 60 90 triangle. The 30-60 side is equal to 2x, here it is 2x=18. The 60-90 side is equal to x. So this side is 18/2=9. The 30-90 side is by the way equal to the root of x, so here the root of 18

4 0

2 years ago

If m∠D + m∠E = 180°, then ∠D and ∠E are classified as what kind of angles?

Archy [21]

The other person is literally wrong. The answer is D. Supplementary because two angles that add up to 180 are supplementary angles.

3 0

3 years ago

Ashley has an action figure collection of 500 action figures. She keeps 430 of the action figures on her wall. What percentage o

Ksju [112]

Answer: 86%

Step-by-step explanation:

430/500=0.86

0.86x100= 86

86%

7 0

3 years ago