BMAT Thread 2010

Thanks. You learn it in mechanics - the weight always acts at the centre of a bar. You know, like our centre of mass is in the middle of our body. Kind of.

I didn't like this paper much.

Ok, I have a question I dont get:

The weather is dreadful here. It rains on three times as many days as there are rain-free days.
Luckily the daily weather forecast is fairly good. Whether the forecast is for rain or for no rain, it is
correct on nine occasions out of ten.
Which one of the following is the probability that the weather forecast will predict rain tomorrow?

a) 13/20
b) 27/40
c) 3/4
d) 13/16
e) 9/10

Anwser:

Rain = 3 days and No rain = 1 day...

Probability of rain = 3/4; Probability of no rain = 1/4.
Probabilty of predicting correct = 9/10; Probability of predicting wrong = 1/10.

Probability of weather forecast predicting rain + it actually does rain = 3/4 x 9/10 = 27/40
Probability of weather forecast predicting rain + it doesn't rain = 1/4 x 1/10 = 1/40


Probability of weather forecast predicting rain = 28/40 = 7/10.

Which isn't even one of the choices.

This question is quite difficult, but I don't see where I'm going wrong.

Rain = 3 days and No rain = 1 day...

Probability of rain = 3/4; Probability of no rain = 1/4.
Probabilty of predicting correct = 9/10; Probability of predicting wrong = 1/10.

Probability of weather forecast predicting rain + it actually does rain = 3/4 x 9/10 = 27/40
Probability of weather forecast predicting rain + it doesn't rain = 1/4 x 1/10 = 1/40


Probability of weather forecast predicting rain = 28/40 = 7/10.

Which isn't even one of the choices.

This question is quite difficult, but I don't see where I'm going wrong.

Rain = 3 days and No rain = 1 day...

Probability of rain = 3/4; Probability of no rain = 1/4.
Probabilty of predicting correct = 9/10; Probability of predicting wrong = 1/10.

Probability of weather forecast predicting rain + it actually does rain = 3/4 x 9/10 = 27/40
Probability of weather forecast predicting rain + it doesn't rain = 1/4 x 1/10 = 1/40


Probability of weather forecast predicting rain = 28/40 = 7/10.

Which isn't even one of the choices.

This question is quite difficult, but I don't see where I'm going wrong.

Well, that working seems correct.. but its not the right answer. Any more ideas?

I had another question, actually. I was gna ask them both together but i'll post it now: (i think im doing something totally stupid for this one)

-----------------------------------------
Many foods carry an indication of the proportion of the guideline daily intake of various vitamins
that is contained in a specified portion. However, the recommended amounts and portion sizes
vary from country to country.
I bought my two favourite breakfast cereals in three different countries, and was amused to find
the contents were the same, but five of the packets I examined claimed to give 10%, 15%, 20%,
25%, and 30% of the local guideline daily amount of Vitamin C.
Which two of the following could not be the proportion given by the remaining packet?
A 5%
B 12.5%
C 17.5%
D 37.5%
E 50%

Well, that working seems correct.. but its not the right answer. Any more ideas?

I had another question, actually. I was gna ask them both together but i'll post it now: (i think im doing something totally stupid for this one)

-----------------------------------------
Many foods carry an indication of the proportion of the guideline daily intake of various vitamins
that is contained in a specified portion. However, the recommended amounts and portion sizes
vary from country to country.
I bought my two favourite breakfast cereals in three different countries, and was amused to find
the contents were the same, but five of the packets I examined claimed to give 10%, 15%, 20%,
25%, and 30% of the local guideline daily amount of Vitamin C.
Which two of the following could not be the proportion given by the remaining packet?
A 5%
B 12.5%
C 17.5%
D 37.5%
E 50%

Well, that working seems correct.. but its not the right answer. Any more ideas?

I had another question, actually. I was gna ask them both together but i'll post it now: (i think im doing something totally stupid for this one)

-----------------------------------------
Many foods carry an indication of the proportion of the guideline daily intake of various vitamins
that is contained in a specified portion. However, the recommended amounts and portion sizes
vary from country to country.
I bought my two favourite breakfast cereals in three different countries, and was amused to find
the contents were the same, but five of the packets I examined claimed to give 10%, 15%, 20%,
25%, and 30% of the local guideline daily amount of Vitamin C.
Which two of the following could not be the proportion given by the remaining packet?
A 5%
B 12.5%
C 17.5%
D 37.5%
E 50%

Lol, that makes no sense. There's nothing in that question which can allow you to deduce which percentages it can or can't be. Put us out of our misery and tell us where you're getting these bastard questions from.

bet you he's writing these himself

These sorts of crazy questions aren't going to come up in the BMAT. Section 1 of the BMAT is basically the TSA and I've not seen anything that random or stupid. Also those sorts of question don't come up in Section 2. Don't worry about them.