Question
What causes the permanent hardness of
water?Solution
Permanent hardness of water is caused by the presence of soluble salts of chlorides and sulfates of calcium and magnesium. Unlike temporary hardness, which can be removed by boiling, permanent hardness remains unless treated with a chemical process.
An Aeroplane flies along a Square field @ 50, 100, 200 and 400 km/hours respectively. Then find the Average speed of the aeroplane during the whole jour...
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Two guns were fired from the same place at an interval of 20 minutes but a person in a train approaching the place hears the sound 16 minutes 30 seconds...
A bike departs from point X at 9:00 AM toward point Y, traveling at a speed of 45 km/h. Two hours later, a car starts from point X toward point Y at a s...
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Arjun, cycling at a speed of 81 km/hr, can complete one round of a square field in 8 seconds. The radius of a circular field is 4 meters more than each ...
A motorist is traveling at 72 km/h and expects to complete his journey in 1.25 hours. After reaching halfway, he halts for 15 minutes. What should be hi...
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