Explanation

Speed = 90 km/h = 25 m/s

Distance = 25 × 21 = 525 m

Length of tunnel = 525 - 130 = 395 m

Last verified on 22-01-2026

Explanation

Departure: 8:35 a.m.

Arrival: 3:12 p.m.

Convert both times to 24‑hour format:

- 8:35 a.m. → 08:35

- 3:12 p.m. → 15:12

Difference:

15:12 − 08:35

→ (15 – 8) hours = 6 hours

→ (12 – 35) minutes = –23 minutes

→ Borrow 1 hour → 6 hours → 5 hours 60 minutes

→ 60 – 23 = 37 minutes

Total journey: 6 hours 37 minutes

Last verified on 18-01-2026

Explanation

To convert 90 km/h into cm/min:

1 km = 100,000 cm  

1 hour = 60 minutes  

So,  

90 km/h = 90 × 100,000 cm / 60 min  

= 9,000,000 cm / 60 min  

= 150,000 cm/min  

Explanation

If 5 men complete the work in 11 days, then 1 man will take 5 times longer, since work capacity is inversely proportional.

1 man = 11 × 5 = 55 days

Explanation

Step 1: Let A's time = t seconds

- So, B’s time = t + 10 seconds

- B runs 950 meters in t seconds (because when A finishes, B is at 950 meters)

- So B’s speed = 950 / t meters per second

Now use B’s speed to find time B takes to run full 1000 meters:

Time = Distance / Speed = 1000 / (950 / t) = (1000t) / 950

We’re also told that B takes 10 seconds more than A:

So,

(1000t / 950) = t + 10

Multiply both sides by 950:

1000t = 950t + 9500

1000t - 950t = 9500

50t = 9500

t = 190 seconds