Keyhole Issues (CDP- Please help)

[The Happy Tooth]

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Hey all,

I'm just begun my DAT preparation and I'm two tests into CDP (doing only Keyholes right now), and I'm having some major difficulties with many of these problems. I'm averaging ~40-50% right per test. In this post and the one below it, I've selected some of the ones that are hardest for me, and I'd appreciate any help you can give!

In addition, if there's any general advice you can give me for practicing Keyholes, it'd be much appreciated!

1.

For this one, I don't understand the difference between A, B and C.

2.

3.

For this one, what's the difference between A, B, and D?

4.

How do you decide between A and B in this one?

5.

 

[The Happy Tooth]

6.

7.

8.

 

[Lnguyen7]

6.View attachment 193345

7.
View attachment 193346

8.View attachment 193347

I will try to show you the differences that are not difficult to spot. I will not include everything though because on the test, you will not have enough time to spot all the differences.

Try to look for shape first. If shapes are very similar then the sizes must be wrong somewhere.

1.

B and C are different in size comparing to the object. Only A has the same size
2.

The two pieces are different in size, so they will not align perfectly. You can eliminate A. C is no where close. B, D and E are possible. This one is tricky though and I am not sure how to explain it to you, but B is the answer.
3.

You should see the differences from the picture. B is the answer.
4.

Looking at the object from the front view, you should see a tiny gap between the two pieces, so you can eliminate A and B. D can also be eliminated because the gap is just too big. C can be eliminated because there is no square shape. The answer is E.
5.

C and D can be eliminated because there is a space between the two pieces sticking out. E is wrong because there is no open rectangle. B is also wrong because of the wrong size. A is the answer.

I will do the other 3 questions tomorrow unless someone can help you out.

 

[The Happy Tooth]

I will try to show you the differences that are not difficult to spot. I will not include everything though because on the test, you will not have enough time to spot all the differences.

Try to look for shape first. If shapes are very similar then the sizes must be wrong somewhere.

1.
View attachment 193355
B and C are different in size comparing to the object. Only A has the same size
2.
View attachment 193356
The two pieces are different in size, so they will not align perfectly. You can eliminate A. C is no where close. B, D and E are possible. This one is tricky though and I am not sure how to explain it to you, but B is the answer.
3.
View attachment 193357
You should see the differences from the picture. B is the answer.
4.
View attachment 193358
Looking at the object from the front view, you should see a tiny gap between the two pieces, so you can eliminate A and B. D can also be eliminated because the gap is just too big. C can be eliminated because there is no square shape. The answer is E.
5.
View attachment 193359
C and D can be eliminated because there is a space between the two pieces sticking out. E is wrong because there is no open rectangle. B is also wrong because of the wrong size. A is the answer.

I will do the other 3 questions tomorrow unless someone can help you out.

Thank you for helping- two quick follow up questions:

1) If there is a hole in the object/question, but the aperture doesn't have a hole in that position and all other edges/the shape lines up perfectly, can the object still pass through the aperture?

2) how did you mark up the problems with the lines and ovals? And is this allowed on the DAT?

 

[Lnguyen7]

Thank you for helping- two quick follow up questions:

1) If there is a hole in the object/question, but the aperture doesn't have a hole in that position and all other edges/the shape lines up perfectly, can the object still pass through the aperture?

2) how did you mark up the problems with the lines and ovals? And is this allowed on the DAT?

1) Yes, the object will fit, but you want the best fit. Just like you can insert several different keys into the same lock, but only the right key can turn the lock.
2) I used Paint software to draw those lines/ovals just for illustration. This is not allowed on the DAT.

6.

A is wrong because there is no triangle hole.
B is wrong because the middle piece is aligned at the center, but in B it is not.
D is wrong because the two green apexes lie on on top of the rear piece.
E is wrong because if you are looking from the top view, you will not see a triangle shape.

7.

A is wrong because there is a small piece sticking out, but the object is flat.
B is wrong because the aperture is smaller than the actual size.
C is wrong because the hole is a square, but it is not.
D is wrong because there is no gap and the somewhat a square is bigger than the actual size.

8.

A and C are not best fit and thus you can eliminate them.
B is wrong because there should be a hook shape.
E has the hook shape but it is missing the blue part.
D is the answer.

 

[The Happy Tooth]

1) Yes, the object will fit, but you want the best fit. Just like you can insert several different keys into the same lock, but only the right key can turn the lock.
2) I used Paint software to draw those lines/ovals just for illustration. This is not allowed on the DAT.

6.
View attachment 193364
A is wrong because there is no triangle hole.
B is wrong because the middle piece is aligned at the center, but in B it is not.
D is wrong because the two green apexes lie on on top of the rear piece.
E is wrong because if you are looking from the top view, you will not see a triangle shape.

7.

A is wrong because there is a small piece sticking out, but the object is flat.
B is wrong because the aperture is smaller than the actual size.
C is wrong because the hole is a square, but it is not.
D is wrong because there is no gap and the somewhat a square is bigger than the actual size.

8.

A and C are not best fit and thus you can eliminate them.
B is wrong because there should be a hook shape.
E has the hook shape but it is missing the blue part.
D is the answer.

Thank you very much for your help!
Can you clarify what you meant by "looking from the top view, you will not see a triangle shape" for #6E?

This is helping a lot.
Also, am I going about this the right way by just practicing CDP problems? Should I be doing something differently/checking out certain Youtube guides/etc?

 

[Lnguyen7]

Thank you very much for your help!
Can you clarify what you meant by "looking from the top view, you will not see a triangle shape" for #6E?

This is helping a lot.
Also, am I going about this the right way by just practicing CDP problems? Should I be doing something differently/checking out certain Youtube guides/etc?

If you look at the triangular shape from the top view (as if you were looking at your feet), you will see a rectangle (as in choice B). You will not see any irregular hexagon.

You just need to practice more and pay attention to detail. Ignore the timer when doing these practices, try to understand and train your eyes first. There are several youtube guides that are helpful but not all of them might work for you. You just have to find the one that works for you.

 

[dentalfan99]

how the hell is this a half circle??

 

[Ari Rezaei]

View attachment 193382
how the hell is this a half circle??

Check out the rectangle in front of the circle. You're completely right that there is indeed a circular cutout, but you always have to consider the entire shape when doing keyhole problems. The rectangle covers half of the circle from the front-back view.

 

[ns718]

If you look at the triangular shape from the top view (as if you were looking at your feet), you will see a rectangle (as in choice B). You will not see any irregular hexagon.

You just need to practice more and pay attention to detail. Ignore the timer when doing these practices, try to understand and train your eyes first. There are several youtube guides that are helpful but not all of them might work for you. You just have to find the one that works for you.

That's a nice way to see it. I didn't see the rectangular shape. Thanks