Explanation

Car A:

• Time = 3 hours 20 minutes = $3 + frac{20}{60} = 3.33$ hours

• Distance = 300 km

Car B:

• Time = 2 hours 80 minutes = 2+80/60​=3.33 hours

• Distance = 280 km

Total Distance

$$300 , text{km} + 280 , text{km} = 580 , text{km}$$

Total Time

$$3.33 + 3.33 = 6.66 , text{hours}$$

Average Speed Formula:

$$text{Average speed} = frac{text{Total Distance}}{text{Total Time}} = frac{580}{6.66} approx 87.09 , text{km/h}$$Total Time=580/ 6.66​≈87.09km/h

$$$$
boxed{87.1 , text{km/h (approx)}}

Explanation

Given:

Dishwasher washes 12 dishes in 6 minutes

Time = 3 hours = 180 minutes

Step 1: Dishes per minute

12 dishes / 6 minutes = 2 dishes per minute

Step 2: Total dishes in 180 minutes

2 × 180 = 360 dishes

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.

Explanation

Given:

• Speed from A to B = 40 km/h

• Speed from B to A = 40 km/h + 50% of 40 km/h = 40 + 20 = 60 km/h

Find:

Average speed for the whole journey (both ways).

Formula for average speed when distance is the same but speeds differ:

Plug in values:

=4800/100

=48 km/h

Explanation

If a sum becomes 3 times in x years, and you're using compound interest, then:

• In 2x years, it becomes $3\times 3=9$ time

• In 3x years, it becomes $3\times 3\times 3=27$ time

So, if the sum triples in 4 years, it becomes 27 times in $4\times 3=12$ years.