Which of the following are wrong?
I. Na2CO3 is used in softening hard water
II. NaHCO3 is used for bleaching cotton and linen in textile industry
III. Caso4 1/2(H2O) is used for plastering fractured bones
IV. CaOCl2 is used in making of baking powder
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Focal length of a convex mirror whose radius of curvature 40 cm is |
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A man has to exert a force of 10 N at the edge of a door to push it open. How much,force will the man have to exert if he pushes the centre of the door? |
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The first battery was made by |
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The average height of 12 students in a class was calculated as 152 cm. On verification it was found that one reading was wrongly recorded as 148 cm instead of 172 cm. Find the correct mean height |
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The difference of the squares of two positive numbers is 45. The square of the smaller number is four times the larger number. Find the numbers |
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The radius of a cart wheel is 35 cm. How many revolution does it make in travelling a distance of 154 m |
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Saran is 6 times as old as his son Sankar. After 4 years, he will be 4 times as old as |
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Express 0.35(bar) into fraction |
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How many numbers are there between 200 and 300 which are exactly divisible by 6,8 and 9? |
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A can do a piece of work in 20 days and B can do it in 30 days. How long will they take to do the work together? |
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