Explanation

Since 12 pumps can empty the tank in 20 minutes, the rate at which they empty the tank is 1 tank / 20 minutes.

With 2 pumps out of order, we have 12 - 2 = 10 pumps left. Since the rate is directly proportional to the number of pumps, the rate of the remaining 10 pumps is:

10/12 × (1 tank / 20 minutes) = 1 tank / 24 minutes

So, the remaining 10 pumps will take 24 minutes to empty the tank.

Explanation

In this scenario, we can use the tangent function, which is the ratio of the opposite side (height of the tower, h) to the adjacent side (the horizontal distance, 70m):

Explanation

To find how many shirts the washerman can iron in one hour (60 minutes), we can use the given rate:

• The washerman irons 4 shirts in 12 minutes.

Now, let's find how many sets of 12 minutes are there in 60 minutes:

60​/12=5

Since he can iron 4 shirts in 12 minutes, in 60 minutes he can iron:

4×5=20 shirts

Explanation

To solve this, we can start by expressing the given ratio m:n = 3:2 in terms of a variable, let's say x. So, m = 3x and n = 2x.

Now, let's substitute these expressions into the given ratio (4m+5n):(4m-5n):

(4(3x) + 5(2x)) : (4(3x) - 5(2x))

Expanding and simplifying, we get:

(12x + 10x) : (12x - 10x)

22x : 2x

Now, we can divide both terms by 2x to get: 11 : 1

Explanation

To find the answer, we calculate the total work:

42 women x 18 days = 756 woman-days

Since the work remains the same, we divide the total work by 21 days:

756 woman-days ÷ 21 days = 36 women

So, 36 women can do the same work in 21 days.

Explanation

Work done by 8 men or 12 women in 25 days:

Work done by 8 men in 25 days = 1 complete piece of work.

Work done by 12 women in 25 days = 1 complete piece of work.

Explanation

60 women spin 48 kg of cotton in 8 hours.

First, find the total hours worked by 60 women: 60 women x 8 hours = 480 hours.

Now, find the total cotton spun per hour: 48 kg ÷ 480 hours = 0.1 kg/hour.

Since 30 women work 12 hours daily, find their total hours: 30 women x 12 hours = 360 hours.

Finally, find the total cotton spun by 30 women: 360 hours x 0.1 kg/hour = 36 kg.

So, the correct answer is: 36 kg

Explanation

To convert hours and minutes to just minutes:

3 hours = 3 × 60 = 180 minutes

30 minutes = 30 minutes

So, the total time = 180 + 30 = 210 minutes

Explanation

Convert the speed of the train from km/hr to m/s:

45 km/hr = 45 × 1000 m / 3600 s = 12.5 m/s

The train crosses the bridge in 30 seconds, so the total distance covered is the length of the train plus the length of the bridge. Let's call the length of the bridge "x". Then, the total distance = 130 m (train length) + x.

Since the train crosses the bridge in 30 seconds, we can use the formula:

Distance = Speed × Time

Substitute the values:

130 m + x = 12.5 m/s × 30 s

Simplify the equation:

130 m + x = 375 m

Subtract 130 m from both sides:

x = 245 m

So, the length of the bridge is 245 m.

Explanation

250 mm + 350 mm = 600 mm  

Since 10 mm = 1 cm,  

600 mm ÷ 10 = 60 cm