TYS 'O' LVL maths question

gunner77 SG

then 8004000?

i thought

eight hundred and four thousand is 804000?

tinuviel07 SG

yep

gunner77 SG

then my answer correct wat

804000,700000, 687000

how come the answer sheet put

0.7 million, eight hundred and four thousand, 687000

gunner77 SG

OHH !

i noe why liao

i read the question wrongly !

wat a joke~

gunner77 SG

must be those stress la

tinuviel07 SG

then my answer correct wat

804000,700000, 687000

how come the answer sheet put

0.7 million, eight hundred and four thousand, 687000

the ans bk guai lan lor

gunner77 SG

tin are u good at physic?

tinuviel07 SG

don't like physics but u can try

Ahm97sic SG

Hi tinuviel07,

There is another actual past "O" level E. Maths question that requires even more working ie an amount is deposited at a compound interest of 10% per annum for 3 years, at the end of the 3rd year, there is $532.40 in the account, what is the original amount deposited ?

So, please help him to learn both methods. Ok.

Regards,

ahm97sic

gunner77 SG

hmm ok, not today

next few days.

i dont have anymore maths question for today.

tmr im going to finish the last TYS paper 1 !

and im gonna focus on phyics and chem!

tinuviel07 SG

ok gunner boy boy.. please try said qn haha

gunner77 SG

no phyics question

but i ask u chem

sulphuric acid + sodium hydroxide ---> sodium sulphate + water

sodium ions have been

- oxidised

-reduced

-neither of them

which one?

tinuviel07 SG

no phyics question

but i ask u chem

sulphuric acid + sodium hydroxide ---> sodium sulphate + water

sodium ions have been

- oxidised

-reduced

-neither of them

which one?

H2SO4 + NaOH => Na2SO4 + H2O

If you look in terms of oxidation number, all the oxidation number did not change.

E.g. Na is still +1 in NAOH or Na2SO4,

Sulphur is still +6.

So means neither lor.

gunner77 SG

one more question

suggest one test which you could distinguish between alcohol and acid.

state the result as well.

tinuviel07 SG

one more question

suggest one test which you could distinguish between alcohol and acid.

state the result as well.

Hmmm for o level standard,

you can just use your acid tests.. Like

acid + metal = > produces H2 gas. test for H2 gas.

acid + carbonate => produces carbon dioxide gas. test for CO2 gas

gunner77 SG

H2SO4 + NaOH => Na2SO4 + H2O

If you look in terms of oxidation number, all the oxidation number did not change.

E.g. Na is still +1 in NAOH or Na2SO4,

Sulphur is still +6.

So means neither lor.

ohh!

but my friend explain to me this way

acid and alkali ---> neutralisation takes place so no change.

like tat also can?

tinuviel07 SG

it must be observable for you to know whether something has taken place.. no visible observation does not necessary means neutralisation has taken place. it can mean other reactions too

gunner77 SG

ok ok

no more liao

i hate the chem TYS

the answer at the back alot of them dont have one

gunner77 SG

anyways thanks !

tmr then i ask u more

thanks for all the help!

tinuviel07 SG

yup yup.. i hate it too.. last time i was thinking do for what.. i also dono correct or wrong..

anyway np..

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