Help with proportion problems: earnings, picture enlargement, and fractions

[simplywrite]

This has been racking my brain for awhile, and I know I have it right, but something is missing.

1. A person earns 850 euros in one week. How much will she earn in 3.5 weeks?

This seemed simple enough, so I just multiplied 850 by 3.5 and got $2,975. I know there's one more step, and I can't find it.

2. A picture is 73/4 inches wide and 81/2 inches high. If you wish to enlarge the width to 10 inches, how high will the picture be? Express in fractions instead of decimals.

I converted the fractions into decimals so I can get the fraction answer. I came up with 7.75/8.5 = x/10 = I then got 77.5 over 8.5 and came up with 911/100. Obviously this is wrong, but I can't figure out the step I missed here.

3. There's 5/4 of a triangle and 2/x of another one, I'm supposed to find the missing piece.I come up with 8/5. I'm stuck on where to go from here.

Any help would be appericated.

 

[Doc Al]

1. A person earns 850 euros in one week. How much will she earn in 3.5 weeks?

This seemed simple enough, so I just multiplied 850 by 3.5 and got $2,975. I know there's one more step, and I can't find it.

This one's just fine---no missing steps.

2. A picture is 73/4 inches wide and 81/2 inches high. If you wish to enlarge the width to 10 inches, how high will the picture be? Express in fractions instead of decimals.

I converted the fractions into decimals so I can get the fraction answer. I came up with 7.75/8.5 = x/10 = I then got 77.5 over 8.5 and came up with 911/100. Obviously this is wrong, but I can't figure out the step I missed here.

You messed up the statement of ratios. It looks like you tried to use:
$$\frac{W_1}{H_1} = \frac{W_2}{H_2}$$
But you put $H_2 = 10$ instead of $W_2 = 10$.

3. There's 5/4 of a triangle and 2/x of another one, I'm supposed to find the missing piece.I come up with 8/5. I'm stuck on where to go from here.

I don't understand this problem.

 

[NateTG]

This has been racking my brain for awhile, and I know I have it right, but something is missing.

1. A person earns 850 euros in one week. How much will she earn in 3.5 weeks?

This seemed simple enough, so I just multiplied 850 by 3.5 and got $2,975. I know there's one more step, and I can't find it.

Right. You forgot to account for taxes ;). Just kidding, that looks correct to me.

2. A picture is 73/4 inches wide and 81/2 inches high. If you wish to enlarge the width to 10 inches, how high will the picture be? Express in fractions instead of decimals.

I converted the fractions into decimals so I can get the fraction answer. I came up with 7.75/8.5 = x/10 = I then got 77.5 over 8.5 and came up with 911/100. Obviously this is wrong, but I can't figure out the step I missed here.

I'd suggest staying with fractions if you're comforatable:

So you've got an inital aspect ratio:
$$\frac{width}{height}=\frac{\frac{73}{4}}{\frac{81}{2}}=\frac{146}{324}=\frac{73}{162}$$
and then you want so solve for the same aspect ratio with a different width:
$$\frac{10}{h}=\frac{73}{162}$$
$$10\times162=73 h$$
$$\frac{1620}{73}=h$$

Of course, since $$\frac{73}{4} > 10$$ and the problem mentions increase to 10 inches, I'm guessing you copied it incorrectly.

3. There's 5/4 of a triangle and 2/x of another one, I'm supposed to find the missing piece.I come up with 8/5. I'm stuck on where to go from here.

Any help would be appericated.

I can't quite follow what you're doing, but I'd guess that you'should be getting $$\frac{8}{5x}$$ instead of $$\frac{8}{5}$$.

 

[simplywrite]

The exact problem is

I have two triangles, one is 5 inches on the left and 4 inches at the bottom. Another one is 2 inches on the left side and x on the bottom. The idea is to find the missing piece of that one, that's what I was trying to say.

 

[NateTG]

The exact problem is

I have two triangles, one is 5 inches on the left and 4 inches at the bottom. Another one is 2 inches on the left side and x on the bottom. The idea is to find the missing piece of that one, that's what I was trying to say.

Can you fill in the spaces below?
5 is to 4 as _ is to _

 

[simplywrite]

5 is to 4 as 2 is to x.

One triange is 5 inches on the left, and 4 at the bottom. Another is 2 inches to the left. The idea is to find the x at the bottom of the other triange.

 

[simplywrite]

Let me redo this one:

A picture is 7 3/4 inches wide and is 8 1/2 inches high. If you enlarge the picture by 10 inches, how high will the picture be expressed as a fraction over a decimal?