Ocean diver exam ,,, test paper A ,,, qu 20

[Andy Nye]

20 ) Ocean divers Jane and MArk begin a dive with 210 & 180 bar in thier cylinders respectivly, What contents reading should they plan to turn around / 1/2 way in the dive ?

A .140 bar on either
B .120 bar on either
c .140 on Janes and 120 on Marks
d .105 on Janes and 90 on Marks
e . 90 on either

Now which is the right answer,and why ? coz we are puzzled , coz non of the maths work out right.

Andy

[iainmsmith]

20 ) Ocean divers Jane and MArk begin a dive with 210 & 180 bar in thier cylinders respectivly, What contents reading should they plan to turn around / 1/2 way in the dive ?

A .140 bar on either
B .120 bar on either
c .140 on Janes and 120 on Marks
d .105 on Janes and 90 on Marks
e . 90 on either

Now which is the right answer,and why ? coz we are puzzled , coz non of the maths work out right.

I would have thought that, using BSAC's "Rule of Thirds" (One third down and out, one third back, one third ascent + reserve), the answer is c.

Iain

[Andy Nye]

:=20 ) Ocean divers Jane and MArk begin a dive with 210 & 180 bar in thier cylinders respectivly, What contents reading should they plan to turn around / 1/2 way in the dive ?
:=
:=A .140 bar on either
:=B .120 bar on either
:=c .140 on Janes and 120 on Marks
:=d .105 on Janes and 90 on Marks
:=e . 90 on either
:=
:=Now which is the right answer,and why ? coz we are puzzled , coz non of the maths work out right.

I would have thought that, using BSAC's "Rule of Thirds" (One third down and out, one third back, one third ascent + reserve), the answer is c.

Iain


Cheers Iain

[dave taylor]

Andy
C is the correct answer, based on BSAC's rule of thirds. But the answer should read 140 on Jane's OR 120 on Mark's. I believe this error has been corrected on the DTP errata section of the website...
HTH Dave

[dave taylor]

Andy
C is the correct answer, based on BSAC's rule of thirds. But the answer should read 140 on Jane's OR 120 on Mark's. I believe this error has been corrected on the DTP errata section of the website...
HTH Dave

[richard scarsbrook]

:[snipped]=C is the correct answer....the answer should read 140 on Jane's OR 120 on Mark's..... corrected on the DTP errata section of the website...

Yes (c) is the correct answer using the calculation on pp46-47 of the OD Student Manual, and yes there is a 'correction' on the website. However 'and' in the original version is a conjunction not a logical operator, so the version on the CD remains correct. Only if the question had been different (eg ....."which of the following logical expressions defines their turnround point") would the change to 'or' have been necessary. Either way it's a trivial point likely to be lost on most people. The answer is obvious provided the candidate can do the air calculations, because (c) is the only option with both correct numbers in it.