2018 PSLE Discussions & Strategies (Born in 2006)

[Sctc]

I think the question did mention something like the pistil will fall off first followed by the stamen, meaning that they mature at different timing, that will prevent self pollination. I may be wrong.

[pungg]

But he said they didn’t mention about anything and morover they know about pistil but not in depth.

[puff]

lee_yl:

I am curious why that school teacher and tutor say it’s choice (4).


Btw, a sponge soaked with water is call a solid+liquid mixture. And can a solid ball be hollow, strictly speaking, no, else we are just playing with words

Thanks for the clarify a soaked sponge ball is not consider a solid. Steel solid ball could float on water due to
surface tension with precise calculation. So same material solid ball could sink or float depending on how it is place in the water. This sci qn have too many possibility how to say ans 4 is wrong.

[Iluvmygals]

The more we discuss about the ball question the more it looked like a PHD entrance exam…not a PSLE.

[puff]

Iluvmygals:

The more we discuss about the ball question the more it looked like a PHD entrance exam....not a PSLE.

:laugh:

[abhcbl]

mylilgirl:

pungg:

[quote=\"lee_yl\"]@Mylilgirl,

If answer is indeed B only but current school teacher (and Sc tutor) said it’s “neither”, then I worry for our children.

Probably need to remind kids taking PSLE next year, for simple straightforward questions, don’t think too deeply into it, just move on to the next question.

According to teacher answer is 4, 2 is wrong :roll:

My DD teacher and tutor also confirmed 4 is the correct answer. Happy for her classmates who got it correct.[/quote]All these teachers and tutors very good leh. Never read the exact wording of the question also can tell what is the correct answer. :faint:

PS. Air is also material. Unless there is a vacuum ball... that is thick enough not to be crushed by air pressure


To say B is wrong - you will need to prove that it is possible when they are made from the same material. That should only be possible if one has air inside but the question said solid...so B should be correct and therefore the answer is 2.

[Mum of 3]

Iluvmygals:

While the formula for density is mass/volume, it doesn't mean that a same material will have varying density because of different volume or different mass. So, a big iron ball will have the same density as a small iron ball, even though they have different volume. The density of a material will only change when pressure or temperature changed.


So since the 3 balls existed in the same temperature and pressure, the floating ball will be a different material from the balls that sank. We don't need to know the mass and volume of the balls to conclude that they are of different density, and hence different material.

I agree with this analysis. Since the question specified that those are solid balls, the floating ball and the sunk ball (of different density) must be of different material. The mass and volume does not matter. So the answer should be 2.

[Mum of 3]

Sctc:

I think the question did mention something like the pistil will fall off first followed by the stamen, meaning that they mature at different timing, that will prevent self pollination. I may be wrong.

This is what my DS told me. He also chose the answer: by insects + 2 flowers.

[Mum of 3]

lee_yl:

oneheart:

My gal's answer is 3, she said the drawn diagram in this forum is not accurate. She said there's 9 cubes. Her class has mixtures of 3, 4 and 6 as answers tho. Hopefully she read the questions correctly

Intially, my girl counted 9 cubes from the diagram. But when she read the question again, she realised that the question stated that the figure was made out 8 cubes.

My DS also said he saw 9 cubes in the diagram. His answer is therefore 3, which is wrong since the question stated 8 cubes. Did anyone else see 9 cubes in the diagram?

[smilestaff]

Yup, DC saw 9 cubes also and came up with the answer 3.

How many marks was this question, I read someone say 3 marks, but my daughter says identifying how many sides is the second part of the question worth 1 Mark, the 1st part was to draw the side view which she had it right, hopefully.