Quiz Discussion

25% of 25% Is Equal To

• 1]

  0.0625

• 2]

  0.0210

• 3]

  0.03145

• 4]

  0.3210

An ore contains 25% of an alloy that has 90% iron. Other than this, in the remaining 75% of the ore, there is no iron. How many kilograms of the ore are needed to obtain 60 kg of pure iron?

• 1] 250 kg
• 2] 275 kg
• 3] 300 kg
• 4] 266.66 kg

In an examination 80% candidates passed in English and 85% candidates passed in Mathematics. If 73% candidates passed in both these subjects, then what per cent of candidates failed in both the subjects?

• 1] 8
• 2] 15
• 3] 27
• 4] 35

The average weight of a class of students is 67.5 kg. The weight of the class teacher is 25% more than the average weight of the class. The average weight of the class is less than the class teacher by x%. The value of x is:

• 1] 33.335
• 2] 25%
• 3] 20%
• 4] 22%

The population of a town increased from 1,75,000 to 2,62,500 in a decade. The average percent increase of population per year is:

• 1]

  4.37%

• 2]

  5%

• 3]

  6%

• 4]

  8.75%

The cost of packaging of the mangoes is 40% the cost of fresh mangoes themselves. The cost of mangoes increased by 30% but the cost of packaging decreased by 50%, then the percentage change of the cost of packed mangoes, if the cost of packed mangoes is equal to the sum of the cost of fresh mangoes and cost of packaging :

• 1] 14.17%
• 2] 7.14%
• 3] 8.87%
• 4] 6.66%

In a factory there are three types of machine M1, M2 and M3 which produces 25%, 35% and 40% of the total products respectively. M1, M2 and M3 produces 2%, 4% and 5% defective products, respectively. what is the percentage of non-defective products ?

• 1] 89%
• 2] 97.1%
• 3] 96.1%
• 4] 86.1%
• 5] None of these

express 62.5% as a fraction

• 1]

  1/2

• 2]

  5/8

• 3]

  3/8

• 4]

  7/8

In a laboratory experiment, a sample of air which is a mixture of oxygen and water vapour is taken. Water vapour, contains hydrogen and oxygen gases. If air contains a total of 70% oxygen (including that contained in the water vapour) by weight while water vapour contains 16.66% of oxygen by weight, how many kilograms of water vapour is present in 1 kilogram of air?

• 1]

  0.20

• 2]

  0.36

• 3]

  0.32

• 4]

  0.25

An inspector rejects 0.08% of the meters as defective. How many will he examine to reject 2?

• 1]

  2000

• 2]

  2200

• 3]

  2500

• 4]

  2800