Adding Time

Discussion in 'Quantitative Aptitude' started by Manjyot, Nov 20, 2008.

  1. Manjyot

    Manjyot Member

    Here is a nice simple way to add hours and minutes together:

    Let’s add 1 hr and 35 mins and 3 hr 55 mins together.

    What you do is this:
    make the 1 hr 35 mins into one number, which will give us 135 and do the same for the other number giving us 355

    Now you want to add these two numbers together:

    135
    355
    ____
    490

    So we now have a sub total of 490. What you need to do to this and all sub totals is add the time constant of 40.

    No matter what the hours and mins are, just add the 40 time constant to the sub total.

    490 + 40 = 530

    So we can now see our answer is 5 hrs and 30 mins!
  2. shabbir

    shabbir Administrator Staff Member

    This is very useful but have you wondered why 40. I would explain it here

    Time has a base of 60 and we are using a base of 10s and 100s and so when we add 40 actually we are converting the base and getting the addition we did on 10s number to 60s base number

    Also the amount of 40 to be added is not always 1.

    Cheers
  3. Handsome

    Handsome Member

    intresting...!
  4. sagarbest

    sagarbest Member

    wow amazing trick it would help in exam.....any more trick plz share with us....
  5. key_3535

    key_3535 New Member

    great yaar
    thanks
  6. ara12321

    ara12321 New Member

    u can also do like this.. u just convert hours into minutes and add the resulting numbers and again convert it into hours...
    1 hr = 60 mins ==> 1 hr + 35 mins = 95 mins
    similarly, 3 hr = 180 mins ==> 3 hrs + 55 mins = 180 + 55 = 235 mins
    therefore, 235 + 95 = 330mins
    ==> 330/60 = 5.30 i.e 5hrs 30 mins.
  7. donold

    donold Member

    I thinks students mus read this.very interesting!
  8. praveer

    praveer New Member

    Hello all the above trick given my manjot is only possible when the minutes are more than 60 for example,

    2:15 + 3:20= 215 + 320 = 535 means 5 hr 35 min so here we are not adding 40 so now,

    if ,
    2:15 + 3:55= 215 + 355 = 570 so here we will add 40 coz the minutes is more than 40.
    so,
    570 + 40 =610 so = 6 hr 10 min...

    plzz do tell mee if somewhere i m wrong....

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