Explanation

Average speed ≠ average of speeds when distances are equal.  

Use: Average speed = Total distance / Total time

Total distance = 60 + 60 = 120 km

Time for 1st part = 60 km / 60 km/h = 1 hour  

Time for 2nd part = 60 km / 120 km/h = 0.5 hour  

Total time = 1 + 0.5 = 1.5 hours

Average speed = 120 / 1.5 = 80 km/h.

Last verified on 13-06-2026

Explanation

Assuming “10 past 5” means 5:10:

- Time elapsed since noon = 5 hours 10 minutes = 310 minutes.

- The hour hand moves 0.5° per minute.

Formula: 30° per hour = 0.5° per minute.

• 5 hours 10 minutes = 310 minutes

• 310 × 0.5° = 155°

  Last updated 08 Nov 2026 by NA

Explanation

First convert 10 minutes into hours:

• 1 hour = 60 minutes $1\text{ hour}=60\text{ minutes}$

• 10 minutes=10/60​=1/6​ hour

Distance = Speed × Time

d = vt

• Speed $v=60$ km/h

• Time $\frac{\mathrm{<span\; style="font-family:\; Overpass,\; sans-serif;\; font-size:\; 0.875rem;">t <span\; style="font-size:\; 0.875rem;">= </span><span\; class="vlist"\; style="font-size:\; 0.875rem;"><span\; class="sizing\; reset-size6\; size3\; mtight"><span\; class="mord\; mtight"><span\; class="mord\; mtight">1</span></span></span></span><span\; class="vlist-s"\; style="font-size:\; 0.875rem;">/6\; h </span></span>}}{}$

d=60×1/6​=10 km

Last updated 08 Nov 2026 by NA

Explanation

To calculate time, use the formula:

$$text{Time} = frac{text{Distance}}{text{Speed}}$$

Given:

• Distance = 25 km

• Speed = 75 km/h

$$text{Time} = frac{25}{75} = frac{1}{3} text{ hours}$$

Since 1 hour = 60 minutes,

1/3​×60=20 minutes

So, the time taken is 20 minutes.

Last updated 08 Nov 2026 by NA

Explanation

Total distance to cover = Train length + Platform length

= 150 + 250 = 400 m

Speed = 60 km/hr = 60 × 5/18 = 50/3 m/sec

Time = Distance / Speed

= 400 / (50/3)

= 400 × 3 / 50

= 24 seconds

Last updated 06 Nov 2026 by NA