B M A T 2008

Hi, could someone please explain how they got 5/12 ?

basically all you do is make b equal all the letters, you should get

a=2b-1
c=10-b
d=b+1
e=b+4

then u do a + c + d + e (all in terms of b) +b = 30
then you get b, then you can get the other numbers

code: 74658

so the train takes 5hrs 40 mins
so the train can arrive with equal probability any time between 2.40 and 3.40
so let's divide it up into a total of 60 mins, of which 35 are after 3.05
35/60 = 5/12

Try this one:

A man wanted to get into his work building, but had forgotten his pin code.
5 clues:

- The fifth number plus the third equals 14
- The fourth number is one more than the second number
- The first number is one less than twice the second number
- The second number plus the third number equals 10
- The sum of all five numbers if 30.

What was his pin code?

Yes but you waste valuable time forming all of those equations. Just input numbers. It should all "spread" from the B.

so the train takes 5hrs 40 mins
so the train can arrive with equal probability any time between 2.40 and 3.40
so let's divide it up into a total of 60 mins, of which 35 are after 3.05
35/60 = 5/12

Hi, could someone please explain how they got 5/12 ?

except 35/60 = 7/12

so the train takes 5hrs 40 mins
so the train can arrive with equal probability any time between 2.40 and 3.40
so let's divide it up into a total of 60 mins, of which 35 are after 3.05
35/60 = 5/12

but how?? In which equation would you start entering values for B? And for every new equation you get there is another variable which you have to follow to make out. In the end you will probably end up with the same amount of time used up.

I couldn't do it with substituting 1-9 but its straightforward rearranging.

ABCDE

E + C = 14
D = B + 1
A = 2B -1
B + C = 10
A + B + C + D + E = 30

So rearrange all in terms of B (since its the most available option)

C = 10 - B
E + 10 - B = 14 --> E = 4 + B

Now all you do is put them all in the long equation

(2B - 1) + (B) + (10 - B) + (B + 1) + (4 + B) = 30
4B + 14 = 30
B= 4

wow all tht to work out just B

and then you got to work out the rest?

harsh lol

If an essay question says to write an argument in favour of this view do we still need to include counter arguments to score highly (>9)?

the answer is 151g

LOOOL I was way off, I got 303 g. Do you mind explaining how you got there please? Am I making some basic stoichiometrical error or something...