Problem Solving

This question seems very easy but I can't get the answer. I think "m" should not be presented in the answer choices

OA is D

Hi Abdulla,

Answer is D.

K kms in "m" minutes. As hours is mentioned, let us convert "m" minutes to hours.

It will be "m/60" hours. Let "x" be the unknown value.

k : m/60 : : x : h

therefore x = 60kh/m.

viju9162 wrote:Hi Abdulla,

Answer is D.

K kms in "m" minutes. As hours is mentioned, let us convert "m" minutes to hours.

It will be "m/60" hours. Let "x" be the unknown value.

k : m/60 : : x : h

therefore x = 60kh/m.

I am always confused with such conversion..

Usually, I write the labels so i don't get confused but in this problem i can't do it.

for example: to convert 1 km/min to meters/h..

1km / 1min * 1000 meter/1km = 1000 meter/1min then * 60 min/ 1h = 10000 meter/ 1h ...

so the km and the min will cancel each others ... but in the above problem I have no idea how to do it.

ohh.. you need not convert km into meter..because the question is in the format " km/minute". Hence, it is enough to convert hours to minutes.

As I described below, let us convert what the question asks for. Then it becomes easier to deduce . Hope this helps.

Regards,
viju

viju9162 wrote:ohh.. you need not convert km into meter..because the question is in the format " km/minute". Hence, it is enough to convert hours to minutes.

As I described below, let us convert what the question asks for. Then it becomes easier to deduce . Hope this helps.

Regards,
viju

My example was a random one.

let's try this one...

k/m min * 60 min/h = 60k/mh ??? what's wrong with it?

lets say rate -> K/M is in units kilometers / minute

If need to convert that M from minutes to hours, just divide that M by 60 .....K/(M/60) = (60 *K)/M ..... units Km/hr

Let's do it this way:

Let k=100 km
Let m=50 min

Let h=6

100 Km---------> 50 min
? ---------> 6 hrs

Convert 6 hrs to min

100 Km---------> 50 min
x? ---------> 6 * 60 min

100/x=50/6*60

6*60 *100/50=x

Now reverse substitute values for 6=h, 100=k and 50=m

h*60*k/m

kh60/m

is the Answer...

Abdulla wrote:

viju9162 wrote:ohh.. you need not convert km into meter..because the question is in the format " km/minute". Hence, it is enough to convert hours to minutes.

As I described below, let us convert what the question asks for. Then it becomes easier to deduce . Hope this helps.

Regards,
viju

My example was a random one.

let's try this one...

k/m min * 60 min/h = 60k/mh ??? what's wrong with it?

You're mixing up the variable h with the unit h above. k/m is in units of kilometers/minute. Multiplying by 60 min/hour gives the result of 60k/m, which is in units of kilometers/hour. Multiplying this result by h which has the units of hours results in 60kh/m, which has units of kilometers.

Keep units separate in your mind from the variable - they purposely called the variables h,k,m to confuse you. Rename them to x,y and z if you like to avoid confusion with the abbreviation for the UNITS

appreciate it if anyone one tell me why C is wrong ? k/ m = rate -----> convert to k/h -----> k/60m ------> distnce traveled = rate * time ====> kh/60m

Please help

Hi Heshamelaziry,

Once you converted "h" into "m" ( .i.e hours into minutes), why are you again multiplying the result with "h" ( hour) again.

As I mentioned in the below loop, it is enough to convert hours into minutes as the question demands it.

Regards,
Viju

viju9162 wrote:Hi Heshamelaziry,

Once you converted "h" into "m" ( .i.e hours into minutes), why are you again multiplying the result with "h" ( hour) again.

As I mentioned in the below loop, it is enough to convert hours into minutes as the question demands it.

Regards,
Viju

Then, should it be kh/60 ?

It cannot be kh/60 because the equation will look like this:

k : m/60 : : x : h

X is unknown value.. by cross-multiplying, you will get the right answer.

Hi Abdulla,

Solution can be explained in the following way...

Car is travelling at k km/m-mins
So we will approach this prob by basic caluculations, no need of any formulae..

For m Mins ---> K Kms(Distance Travelled)
For 60 Mins----> d = ?

This gives d = 60k/m per hr.

So by the above caluculation we hav got for 1 hr distance travelled is 60k/m.

1 hr ---> 60 k/m
h hrs ---> D = ?

This gives value D as 60kh/m.

Rgds,
AVR.