0Lucky0 wrote:
Jaya6 wrote:
Hi,
Plugging in F=45 in the formula would have been the easiest resort which results in option 65/9. THIS is a big TRAP.
the question clearly mentions, the difference or the change is 45F and hence I have assumed values.
I took day 1, F=100 hence after applying the formula C becomes 340/9= 37 (just taking the integer values)
Day 2 F=145 and C becomes 565/9= 62
the difference then becomes 62-37=25 degrees Celsius for a change in 45 degrees F.
option C
Hope this is useful:)
Please hit Kudos, if you like it.
chetan2u, Why can we use the difference between other units and not the difference between Fs?
For eg, the difference between 4 meters and 10 meters is 6 meters. We don't need to convert 4 meters and 10 meters separately, we can just convert 6 meters to cms.
Similarly, we don't need to calculate the kilogram values separately or any other unit's value separately and we can simply convert the difference to the other unit. Why doesn't it work here?
I don't understand. If you could please help me understand this, would be of great help.
Thanks a lot
Hi 0Lucky0,
You CAN approach this question in the way that you're asking about, but you have to do a little work first (to manipulate the given formula so that you better understand the relationship between 1 degree of F and 1 degree of C). As an aside, this question can be solved rather easily by TESTing VALUES (as Brent has shown in his post). In addition, the answer choices are sufficiently 'spread out' that we can use a little logic and a little math to answer this question without too much work.
The equation 9C = 5(F - 32) can be 'rewritten' as...
C = 5(F - 32)/9
C = (5/9)(F - 32)
5/9 is a little more than 1/2.... so we can 'rewrite' the equation again as....
C = (a little more than 1/2)(F - 32)
Thus, for every degree that F 'changes', the value of C will change by a little more than 1/2 of a degree.
In this question, F changes by 45 degrees, so the value of C will change by (a little more than 1/2)(45) degrees. Half of 45 is 22.5, so we're looking for an answer that's a little more than 22.5 degrees. There's only one answer that matches...
GMAT assassins aren't born, they're made,
Rich
Contact Rich at: Rich.C@empowergmat.comThanks for your reply.
Really appreciate it.
However, I did see yours and Brent's explanations above and my doubt remained so the reason why I asked
.
As far as I can tell, It looks like a copy/paste from above, so unfortunately my doubt still remains.