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

Explanation

Distance is directly proportional to speed when time is constant (12 : 9 = 4 : 3).

Solving the ratio gives the original distance as 30 km, so the increased distance is 30 + 10 = 40 km.

Explanation

Total food = 900 men × 30 days = 27,000 man-days

Men left = 900 - 150 = 750

Food will last = 27,000 man-days / 750 men = 36 days