Video summary

10 Extremely Important Types to get 45+ in Maths in SSC Selection Post Phase 14 Exams 2026

Main summary

Key takeaways

Educational

Main Ideas / Concepts

  • The speaker reviews the likely question types for SSC Selection Post Phase 14 Mathematics, noting that similar patterns will appear in SSC CGL shortly after.
  • The focus is on “10 extremely important types” to practice for high marks (45+).
  • For each topic, the speaker highlights either:
    • Sub-types that commonly appear (with examples), and/or
    • A shortcut/method to solve common formats quickly.

Methodology / Instruction-Style Content (Organized by Topic)

1) Mensuration (especially “melting”/mixed solids and surface area)

What to expect

  • 3–5 questions out of 25 in the upcoming/observed shift.
  • Common themes:
    • Melting problems (volume equivalence of transformed shapes)
    • Total surface area (TSA) and curved surface area (CSA)

Key solving hacks

  • Melting / volume equivalence approach

    • If different solids “transform” into a new solid, use the shortcut:
      • Equate volumes.

    • Example structure:

      • Given cubes with edges such as 6, 8, 10 (implied).

      • Compute combined volume: [ 6^3 + 8^3 + 10^3 ]

      • Let the equivalent new cube have volume (v^3).

      • Take cube root to get the missing edge.

  • Cone + sphere / cone–sphere volume balancing

    • Use volume formulas and set them equal:
      • Sphere: (\frac{4}{3}\pi r^3)
      • Cone: (\frac{1}{3}\pi r^2 h)
    • Then solve after equating.

  • TSA/CSA formula practice

    • Memorize formulas for:
      • 2D figures and 3D figures
      • Volume, CSA, TSA
    • Recommendation:
      • Watch an existing dedicated 40–50 minute mensuration video
      • Practice questions after memorizing formulas.

2) Trigonometry (simplified identities using sec and tan)

Expected pattern

  • Questions where values like (\sec\theta + \tan\theta) are given, and you need to find another value such as (\sin\theta).

Core technique

  • If: [ \sec\theta + \tan\theta = 3 ] then: [ \sec\theta - \tan\theta = \frac{1}{3} ]

  • Add/subtract to eliminate:

    • (2\sec\theta = 3 + \frac{1}{3})
  • Then:
    • Find (\sec\theta \Rightarrow \cos\theta)
    • Use (\cos\theta \Rightarrow \sin\theta)

Related shortcut mentioned

  • Triplet-style scaling
    • If you get (\sin\theta = \frac{4}{5}), use scaling to obtain integer-friendly answers.
  • Triangle/triplet substitution may also be used when applicable:
    • Related expressions like: [ 3\sec\theta,\; 4\tan\theta,\; 2\cot\theta,\; \csc\theta ]

3) Mixture & Alligation

Expected pattern

  • Two/more containers with mixture ratios (e.g., milk and water).
  • You must find the mixing ratio so the final ratio matches a target.

Method

  • Model each container’s milk-water composition using the given ratio.
  • Use an allegation-style difference/combination approach (with fraction-based working).
  • Conceptual “pure quantity” trick:
    • Assume pure milk = 100
    • If 20% is replaced by water → milk becomes 80
    • Repeat substitution logic for multiple replacements
    • This effectively multiplies the remaining fractions to compute the final percentage.

4) Time & Work

What to do

  • Practice the basic time-and-work questions that appeared that day.
  • The speaker suggests:
    • Screenshot or note those questions
    • Practice using their basic pattern
  • Also mentioned:
    • A separate one-shot video covering all Time & Work types.

5) Interest (CI vs SI; payment frequency changes)

A) Difference between CI and SI

  • Remember: [ \text{CI} - \text{SI} = \frac{p\cdot r^2}{100} ]

  • Procedure when difference is given:

    • Example: difference (=160), principal (p=25000)

    • Solve: [ 160 = \frac{p\cdot r^2}{100} ]

    • Simplify/cancel zeros to extract (r).

B) CI when payment frequency changes (yearly vs half-yearly)

  • Approach mentioned:
    • Treat half-yearly investment growth as separate blocks
    • Example logic:
      • If yearly rate is 8%, then half-yearly periods act like two periods of 4%
    • Use the tree method.

6) Algebra (values of expressions like (x+\frac{1}{x}), higher powers)

Expected patterns

  • Given (x + \frac{1}{x}), find:
    • (x^3 + \frac{1}{x^3}) (via options/identities)
  • Also mention:
    • (x^6 + \frac{1}{x^6})

Method guidance

  • For cube outcomes:
    • Use option-based checking by comparing candidate cubed values.
  • For higher powers:
    • Suggested order:
      1. Start with (x + \frac{1}{x})
      2. Square it to get (x^2 + \frac{1}{x^2})
      3. Proceed further from there (instead of cubing first).

7) Average (alligation-style; age average “evergreen”)

A) Average with pass/fail

Typical structure

  • Total students and averages for:
    • Overall average
    • Passed average
    • Failed average

Method (difference-from-overall logic)

  • Use overall average (=50)
  • Passed average (=70), Failed average (=30)
  • Compute differences:
    • (70 - 50 = 20)
    • (50 - 30 = 20)
  • Since differences match:
    • Passed : Failed = 1 : 1
  • Then use total count to calculate actual numbers
    • Example: total (=120 \Rightarrow) passed (=60)

B) Evergreen: average ages with teacher

  • Average of (students + teacher) is 17
  • If teacher is removed:
    • average of 10 students becomes 2 years less (so it becomes 15)
  • Teacher’s age is found by distributing the difference across counts (speaker arithmetic leads to 37).

8) Speed, Distance, Time (average speed via LCM / scaling)

Expected patterns

  • Successive segments with different speeds.
  • Another type: part distance at one speed and the rest at another.

Method for successive equal-distance segments

  • Distances like “12 km” may be used as intentional confusion.
  • Use LCM of speeds (example: 20, 30, 60 ⇒ LCM = 60).
  • Scale the segment distances so that each segment pattern uses total scaled distance = 60.

  • Time: [ \text{Time}=\frac{\text{distance}}{\text{speed}} ]

  • Total time → compute average speed: [ \text{Average speed}=\frac{\text{total distance}}{\text{total time}} ]

Method for fractional distance at different speeds

  • Example:
    • (2/5) at speed 40
    • (3/5) at speed 60
  • Use total time to set up equations:
    • time for each part = (part distance)/(speed)
  • Solve for total distance.

9) Ratio & Proportion

Type A: percentage change in fraction

  • Numerator increased by 20%
  • Denominator decreased by 10%
  • Convert numerator and denominator accordingly, then compute simplified ratio (x/y).

Type B: (P) is 30% of (R); (Q) is 40% of (R)

  • Compute: [ \frac{P}{Q}=\frac{30\% \cdot R}{40\% \cdot R}=\frac{30}{40}=0.75 ]

  • So (P) is 75% of (Q).

10) Geometry

Type A: Triangle with (XY \parallel BC) and equal-area division

  • Setup:
    • In triangle (ABC), line segment (XY \parallel BC)
    • (X) on (AB), (Y) on (AC)
    • (XY) divides triangle (ABC) into two equal-area regions
  • Key inference:
    • Equal areas imply a relationship between the linear ratios.
    • Use:
      • Area ∝ (side)(^2)
    • Compute the required ratio such as (AX:XB).

Type B: Similar triangles area ratio → altitude ratio

  • Rule for similar triangles: [ \frac{\text{Area}_1}{\text{Area}_2}=\left(\frac{h_1}{h_2}\right)^2 ]

  • Therefore: [ \frac{h_1}{h_2}=\sqrt{\frac{\text{Area}_1}{\text{Area}_2}} ]

  • Example mentioned:

    • If area ratio is (5:3), then: [ \frac{h_1}{h_2}=\sqrt{\frac{5}{3}} ]

Other geometry reminders

  • Topics likely to appear:
    • common tangents
    • circle segment area questions
  • Speaker claims:
    • questions were not very tough
    • the paper was mostly PYQ-based

Sources / Speakers Featured

  • Single speaker: an unnamed instructor/host addressing “hello everyone” and giving solution strategies.
  • Additional sources mentioned (reference only):
    • Mensuration video (40–50 minutes)
    • Trigonometry-related video (planned/mentioned)
    • One-shot Time & Work video
    • Arithmetic and Advanced videos totaling ~10:30 hours
    • Planned “top 50 concepts” videos on 21st and 27th (by the same instructor)

Original video