Math Boost ⚡ Time & Distance PYQ Trick | Solve in Seconds Without Formula | Exam Smart Shortcut #yt, by Focus40 Academy on YouTube. 1 min 38 s.
- Video length
- 1 min 38 s
- Time to do it
- 15 minutes
- Difficulty
- Easy
- Steps
- 8
What you need
Steps
Read the question once and write down the three quantities it gives: distance, speed and time. Mark which one is missing, because that is what you solve for.
Convert every value to one unit system before calculating. To change km/h to m/s, multiply by 5/18. To go back, multiply by 18/5.
When the distance stays the same, skip the formula. Time is inversely proportional to speed, so a speed twice as fast takes half the time.
If a journey covers equal distances at two different speeds, use average speed = 2xy/(x+y). Do not take the plain average of the two speeds.
Use ratios for comparison questions. If two speeds are in the ratio a:b over the same distance, the times are in the ratio b:a.
For train questions, add the train length to the platform or bridge length to get total distance. For a pole or a person, use the train length alone.
Estimate the answer roughly first, then check which option is closest. This catches unit slips and saves a full recalculation.
Practise five previous year questions daily with a timer. Note the ones you solve slowly and redo only those the next day.
Tips and common mistakes
Never average two speeds directly unless the times are equal, or you will get the wrong answer.
Write units beside every number as you go, since most errors come from mixing km/h with m/s.
Memorise common fraction to decimal values so division takes seconds instead of a rough calculation.
If a question looks long, look for a ratio first. The equation route is usually the slowest one.
Questions
How do I convert km/h to m/s quickly?
Multiply by 5/18. For example, 72 km/h becomes 72 x 5/18 = 20 m/s. Reverse it by multiplying by 18/5.
What is the shortcut for a train crossing a platform?
Add the train length and the platform length to get the total distance, then divide by the train speed. For a pole, use only the train length.
Why does my accuracy drop when I try to go faster?
Usually it is unit mixing or skipping the estimate step. Convert units first and do a rough answer check before choosing an option.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
