Reviewer Page Guides

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159

Civil Service Commission Professional or Sub-Professional Reviewer - Page 85/159

Mathematics Test III Solution - Page 85

18. What part of an hour elapses between 9:52 AM and 10:16 AM ?

= 10:16 - 9:52

10:16 is also equal to 9:76 since 76 is equal to 1 hour and 16 minutes. 9 hours + 1 hour and 16 minutes = 10:16.

= 9:76 - 9:52 = 24 minutes

= 24 minutes x    1 hr   
                       60 min

=  24 / 60 hrs.

= 2 / 5 hours *Ans.

19. If the ratio of boys to girls is 3 : 7 . If the class has 40 students, how many additional boys are needed to enroll to make the ratio 2 : 1 ?

3x + 7x = 40      The number of boys : 3x = 3(4) = 12

      10x = 40      The number of girls  : 7x = 7(4) = 28

          x =  40     since the desired ratio of boys to girls
                 10     is 2 : 1 .

          x = 4        the required number of boys is 2 x 28 = 56
                          so 56 - 12 = 44 more boys are needed. *Ans.

20. If 45 feet of uniform wire weigh 5 kilograms, what is the weight of 30 yards o the same wire ?

Let x - be the length of 30 yards of the same wire.

30 yards x  3 feet  = 90 feet
                  yard

 x  =  5 
90    45

 x  =  1 
90     9

x = 10 kgs. *Ans.

21. A school has enough oatmeal to feed 15 children in 4 days. If 5 more children are added, how many days will the oatmeal last ?

This problem is an example of an inverse proportion.

4 : 1/5 = x : 1 / (15 + 5)

4 : 1/15 = x : 1/20

 1 x = 4 ( 1 )
15          20

 x  =  1 
15    5

x =  1  (15)
       5

x = 3 days *Ans.

Civil Service Reviewer Post 85/159