BITSAT · Strategy · 4 October 2026
BITSAT: how to answer a question in about 80 seconds
BITSAT has long given about 80 seconds per question. Check the current pattern on the official BITS admission site, but the skill is the same every year: reach the right option by the shortest path that is still correct.
1. Check dimensions before you calculate
If only one option has the right dimensions, you are done. Energy is force × distance, power is energy per time, and anything inside sin, log or e^ must be dimensionless. It takes seconds and often removes two options.
2. Try a limiting case
Put an extreme value into each option: θ = 0°, a mass going to zero, an angle of 90°, a resistance going to infinity. The correct formula must give a sensible result. For a block on an incline, the acceleration must become g sin 90° = g when the incline is vertical.
3. Eliminate, then decide
Cross out options that break a unit, a sign or a known limit before solving anything. With two options left, a rough estimate usually decides it.
4. Approximate on purpose
Take g = 10 m/s² when the options are far apart, round √2 to 1.41 and π to 3.14, and use (1 + x)ⁿ ≈ 1 + nx when x is small. Exact arithmetic is only worth the time when the options are close.
5. Skip in the first pass
Answer everything you can do in under a minute first. Mark the rest and come back. One stuck question can cost the time of three easy ones.
When does guessing help?
With +3 for a correct answer, −1 for a wrong one and four options, a blind guess is worth 0.25 × 3 − 0.75 × 1 = 0 on average — it neither helps nor hurts. Rule out even one option and a guess among the remaining three is worth (1/3) × 3 − (2/3) × 1 ≈ +0.33. So guess only after eliminating at least one option. (Re-check the marking scheme for your year.)
Practise it
In Teengro, set “Preparing for” to BITSAT and every answer ends with a BITSAT speed tip for that type of question.