Find Interview Questions for Johnson and Johnson

• Length of the train = 280 meters

• Length of the tunnel = 220 meters

• Speed of the train = 60 km/h

We are to find the time taken to cross the tunnel.

—

✅ Step 1: Total distance to be covered = length of train + length of tunnel
= 280 m + 220 m = 500 meters

✅ Step 2: Convert speed from km/h to m/s
1 km/h = 5⁄18 m/s
So,
60 km/h = 60 × 5⁄18 = 50⁄3 ≈ 16.67 m/s

✅ Step 3: Use the formula
Time = Distance ÷ Speed
= 500 ÷ (50⁄3) = 500 × 3⁄50 = 30 seconds

—

✅ Final Answer: The train will take 30 seconds to cross the tunnel.

• Length of train = 150 meters

• Length of tunnel = 300 meters

• Time to cross tunnel = 40.5 seconds

—

✅ Step 1: Total distance to be covered = Length of train + Length of tunnel
= 150 m + 300 m = 450 meters

—

✅ Step 2: Use the speed formula:

Speed = Distance / Time
= 450 m / 40.5 s
≈ 11.11 m/s

—

✅ Step 3: Convert m/s to km/h:
1 m/s = 3.6 km/h
⇒ 11.11 × 3.6 ≈ 40 km/h

• 21 mango trees

• 42 apple trees

• 56 orange trees

We want to plant them in rows such that:

• Each row contains only one type of tree

• Each row has the same number of trees

• The number of rows is minimized

🧠 This is a Highest Common Factor (HCF) problem.

We need to find the HCF of 21, 42, and 56.

—

✅ Step 1: Prime factorizations

• 21 = 3 × 7

• 42 = 2 × 3 × 7

• 56 = 2³ × 7

Common factor = 7

✅ HCF = 7

—

✅ Step 2: Find number of rows for each type:

• Mango: 21 ÷ 7 = 3 rows

• Apple: 42 ÷ 7 = 6 rows

• Orange: 56 ÷ 7 = 8 rows

✅ Total rows = 3 + 6 + 8 = 17 rows

—

✅ Final Answer: Minimum number of rows = 17