Percentage Problems and Solutions

• 22. 2 is what percent of 50

  1. 2%
  2. 4%
  3. 6%
  4. 8%

  Answer :

  Option B

  Explanation:

  2/50 * 100 = 1/25 * 100 = 4 %

• 23. A student multiplied a number by 3/5 instead of 5/3. What is the percentage error.

  1. 64%
  2. 65%
  3. 66%
  4. 67%

  Answer :

  Option A

  Explanation:

  Let the number be x,
  then,
  \begin{aligned}
  \frac{5}{3} - \frac{3}{5} = \frac{16}{15}x
  \end{aligned}
  
  Error% = \begin{aligned}
  (\frac{16}{15}x * \frac{3}{5} * 100)% = 64%
  \end{aligned}

• 24. How many litres of pure acid are there in 8 litres of a 20% solution

  1. 1.5
  2. 1.6
  3. 1.7
  4. 1.8
  5. Only argument I is strong
  6. Only argument II is strong
  7. Either I or II is strong
  8. Neither I nor II is strong
  9. Both I and II are strong

  Answer :

  Option F

  Explanation:

  Question of this type looks a bit typical, but it is too simple, as below...
  
  It will be 8 * 20/100 = 1.6

• 25. What will be the fraction of 20%

  1. 1/4
  2. 1/5
  3. 1/10
  4. None of above

  Answer :

  Option B

  Explanation:

  It will 20*1/100 = 1/5

• 26. Two numbers are less than third number by 30% and 37% respectively. How much percent is the second number less than by the first

  1. 8%
  2. 9%
  3. 10%
  4. 11%

  Answer :

  Option C

  Explanation:

  Let the third number is x.
  then first number = (100-30)% of x
  = 70% of x = 7x/10
  
  Second number is (63x/100)
  
  Difference = 7x/10 - 63x/100 = 7x/10
  
  So required percentage is, difference is what percent of first number
  
  => (7x/100 * 10/7x * 100 )% = 10%

• 27. Two students appeared at an examination. One of them secured 9 marks more than the other and his marks was 56% of the sum of their marks. The marks obtained by them are

  1. 42,30
  2. 42,31
  3. 42,32
  4. 42,33

  Answer :

  Option D

  Explanation:

  Let their marks be (x+9) and x.
  Then, x+9 = 56/100(x + 9 +x)
  => 25(x+9)
  => 14 (2x + 9)
  => 3x = 99
  => x = 33.
  So, their marks are 42 and 33

• 28. If number x is 10% less than another number y and y is 10% more than 125, then find out the value of x

  1. 123.55
  2. 123.65
  3. 123.75
  4. 123.85

  Answer :

  Option C