For #1, the first thing you see is a supposed table. I need help creating a table for number 2. For number 5 I am not too sure how to do, the rest I'm just wondering if I did them correctly.

demha wrote:

4.
Q. A boat travels 60 km upstream (against the current) in 5 hours. The boat travels the same distance downstream in 3 hours. What is the rate of the boat in still water?

A. The rate is 4 current.

Let b be the velocity of the boat in still water and c be the speed of the current. Then you have

Solve the two simultaneous equations for b.

demha wrote:

5.
Q. A duck can fly 2400 m in 10 minutes with the wind. Against the wind, it can fly only 2/3 of this distance in 10 minutes. What is the rate of the wind?

A.
How would I do this?

As above you must set up two simultaneous equations and solve them. Let d be the velocity of the duck in still air and w the speed of the wind. The first equation is

I leave you to derive the second equation and solve the them for w.

Last edited by scientia (2012-12-26 23:40:18)

Hi Bobby:
So it would be 40m/a minute?

Hi Scientina:
I'm not too sure how t continue. Could you please help me a little on that?

Hi Bob:
Now how would I create tat chart? I was also wondering, did I do that chart correctly?

Last edited by demha (2012-12-27 01:30:44)

hi

I was also wondering, did I do that chart correctly?

Do you mean this one:

A.
     Amount of milk    Percentage(%)    Amount of buttermilk
1%     x                     (0.01)                    (0.01)x
4%     12                   (0.04)                    (0.04)12
2%     x + 12                   (0.02)                    (0.02)(x + 12)

There's a little error which I have corrected in red.

What I did is say that the first and second row figures for buttermilk must add up to the last row.

multiply by 100 to remove the decimals

Now how would I create tat chart?

In a word problem, I was taught to find out what I must calculate and call that x.

Then summarise all those words in a table with just the essential details.

There is the start mix, the added seeds and the final mix so the table will need three rows after the headings.

And there are three seed types to consider, mix, bluegrass alone, other seeds alone, so that makes three columns.

Rather than putting in % I converted everything into weights in lb.  That keeps it simple.

Row one plus row two must make row three.

I didn't bother with the final entry as it isn't needed to get x.  But you might like to try to complete it for the practice.  You can solve for x using column three as well.  try it.
Bob

hi demha

Not quite.

Seed Weight      Blue Grass      Weight Other Seed
0%     x√                     0.00√              (0.00)(x)X(i)
30%   80√                   0.30X(ii)              (0.30)(80)X(iii)
20%    x + 80√            0.20X(iv)              (0.20)(x + 80)X(v)

(i)  This is the weight of the other seed.  If x lb is added and all is other seed what should go here?

(ii)  Work out 30% of 80 and write the answer here.

(iii)  Work out 70% of 80 and write the answer here.

(iv)  (x + 80) is correct for the first number in this row.  Write an expression for 20% of (x + 80) here.

(v)  And an expression for 80% of (x + 80) here.

Bob

demha wrote:

Hi Scientina:
I'm not too sure how t continue. Could you please help me a little on that?

What are you not too sure of? The two problems are similar, and I did almost all of question 4 for you. Just apply the concept speed = distance / time.

hi demha

Seed Weight      Blue Grass      Weight Other Seed
0%     x                     0.00              (x)(just x will go here I believe)√
30%   80                   24              (0.30)(56)X  just 56 here
20%    x + 80            16X(i)              (0.20)(x + 64)X(ii)


(i)The total amount in this row is x + 80.  20% of it should go here so put 0.2(x+80)

(i)And a similar expression here but this time for 80% of (x+80)

Now you are ready to solve the puzzle.

You can do the blue grass equation:  0 + 24 = 0.2(x+80)

or the other seed equation x + 56 = 0.8(x+80)

These should both give the same answer for x.

Check it works with the original problem.

Q4 and Q5.  I have put the details for both of these into a table as well.  (See below)

These three formulas are equivalent:

The answer will be in metres per minute.

Bob

Hi Bob:
I redid it again:

Seed Weight      Blue Grass      Weight Other Seed
0%     x                     0.00              (x)(just x will go here I believe)
30%   80                   24              (56)
20%    x + 80            0.2(x+80)              (0.8)(x + 80)

Hi Bob:
With your equation, I did the math and gor x = 40, so it will take 40 pounds of no-blue-grass seeds. Am I correct?

Thank you very much guys! I got a 10 on my final review!!