GateAI
Calculus

GATE CSE 2015 Set 3 · Q50

NAT2 marksMedium

Time

The velocity vv (in kilometer/minute) of a motorbike which starts from rest, is given at fixed intervals of time tt (in minutes) as follows: The approximate distance (in kilometers) rounded to two places of decimals covered in 20 minutes using Simpson's 1/3rd1/3^{\text{rd}} rule is _________.

GATE CSE 2015 Set 3 Q50 diagram

Your answerNumerical answer

Enter a value to check

Solution

Step-by-step verified solution

Official answer: 309.33 (±1.5) (±1.5)

Calculus

The distance covered is given by the integral of velocity with respect to time:

S=∫020v(t) dtS = \int_{0}^{20} v(t)\, dt

The motorbike starts from rest, so at t0=0t_0 = 0, v0=0v_0 = 0. The data points with equal step size h=2h = 2 minutes are:

  • t0=0,  v0=0t_0 = 0,\; v_0 = 0

  • t1=2,  v1=10t_1 = 2,\; v_1 = 10

  • t2=4,  v2=18t_2 = 4,\; v_2 = 18

  • t3=6,  v3=25t_3 = 6,\; v_3 = 25

  • t4=8,  v4=29t_4 = 8,\; v_4 = 29

  • t5=10,  v5=32t_5 = 10,\; v_5 = 32

  • t6=12,  v6=20t_6 = 12,\; v_6 = 20

  • t7=14,  v7=11t_7 = 14,\; v_7 = 11

  • t8=16,  v8=5t_8 = 16,\; v_8 = 5

  • t9=18,  v9=2t_9 = 18,\; v_9 = 2

  • t10=20,  v10=0t_{10} = 20,\; v_{10} = 0

Using Simpson's 1/3rd1/3^{\text{rd}} rule with n=10n = 10 (an even number of intervals):

S=h3[(v0+v10)+4(v1+v3+v5+v7+v9)+2(v2+v4+v6+v8)]S = \frac{h}{3} \left[ (v_0 + v_{10}) + 4(v_1 + v_3 + v_5 + v_7 + v_9) + 2(v_2 + v_4 + v_6 + v_8) \right]

Sum of odd-indexed terms:

∑vodd=10+25+32+11+2=80\sum v_{\text{odd}} = 10 + 25 + 32 + 11 + 2 = 80

Sum of even-indexed terms (excluding boundaries):

∑veven=18+29+20+5=72\sum v_{\text{even}} = 18 + 29 + 20 + 5 = 72

Substituting these values into the formula:

S=23[(0+0)+4(80)+2(72)]=23[320+144]=23×464=9283≈309.33 kmS = \frac{2}{3} \left[ (0 + 0) + 4(80) + 2(72) \right] = \frac{2}{3} [320 + 144] = \frac{2}{3} \times 464 = \frac{928}{3} \approx 309.33\text{ km}

Rounding to two decimal places, the distance is 309.33 km (official acceptable range: 308 to 310).

Try the question first, then check your work.

Think the official key or this write-up is wrong?

Report error or challenge

Examiner trap

The misconception this question tests

This Calculus previous year question is Q50 of the GATE CSE 2015 Set 3 paper. Find more GATE CSE PYQs on Calculus in Engineering Mathematics, or browse all GATE CSE PYQs.

Free diagnostic

Where do you stand for GATE?

Take the 20-minute diagnostic: the 3 topics that cost you the most marks, and a rank range. Or sit 5 related Calculus PYQs now with no account.

One GATE CSE PYQ every morning

An official question by email at 7 AM IST, with a link to its verified solution. Unsubscribe in one click.

Calculus in GATE CSE

Calculus has 40 GATE CSE PYQs across 25 papers from 2011 to 2026. 4 of them are 2-mark NAT questions like this one, and GATE CSE 2015 Set 3 has 3.

How GATE tests Calculus

More from GATE CSE 2015 Set 3

Share this solution

A plain-text card for WhatsApp or Telegram study groups.

GateAI solution cardGATE CSE 2015 Set 3 · Q50 · NAT

The velocity v (in kilometer/minute) of a motorbike which starts from rest, is given at fixed intervals of time t (in minutes) as follows: The approximate distance (in kilometers) rounded to two places of decimals covered in 20 minutes using Simpson's 1/3rd rule is …

Topic-wise GATE CS PYQs with verified steps

Independent practice explanation verified by the GateAI team. GATE is conducted by the IITs; question text follows the official paper.