• ( 1 ) If the cost of k metres of cable wire is c rupees, then what is the cost of m metres of cable wire at the same rate?

    • 1) Rs. (mc)
    • 2) Rs. (mc/k)
    • 3) Rs. (kc)
    • 4) Rs. (km/c)
    • Discussion in forum
      Answer : 2) Rs. (mc/k)
      Solution : Cost of k metres = Rs. C
      Cost of 1 metre = Rs.(c/k)
      Cost of m metres = Rs.[(c/k).m] = Rs.(mc/k)








      discussion


      Answer : 2) Rs. (mc/k)

    • ( 2 ) If 8 goldsmiths, working 9 hours a day, can make 20 ornaments in 24 days, how many ornaments will 18 goldsmiths make in 36 days, each working 8 hours a day?

    • 1) 126
    • 2) 60
    • 3) 92
    • 4) 138
    • Discussion in forum
      Answer : 2) 60
      Solution :
      Goldsmiths 8 : 18 His/Day   9 : 8 Days   24 : 36 : : 20 : x
      => 8 * 9 * 24 * x = 18 * 8 * 36 * 20
      => or x = 60








      discussion


      Answer : 2) 60

    • ( 3 ) Running at the same constant rate, 6 identical machines can produce a total of 270 pens per minute. At this rate, how many pens could 10 such machines produce in 4 minutes?

    • 1) 1500
    • 2) 1545.6
    • 3) 1640.33
    • 4) 1800
    • Discussion in forum
      Answer : 4) 1800
      Solution : Let the required number of bottles be x.
      More machines, More bottles (Direct Proportion)
      More minutes, More bottles (Direct Proportion)
      Machines       6 : 10 Time(in minutes)   1 : 4 :: 270 : x
      => 6 * 1 * x = 10 * 4 * 270
      => x = (10 * 4 *270)/6
      => x = 1800








      discussion


      Answer : 4) 1800

    • ( 4 ) If 17 labours can dig a ditch 20 m long in 18 days, working 8 hours a day; how many more labours should be engaged to dig a similar ditch 39 m long in 6 days, ech labours working 9 hours a day?

    • 1) 34
    • 2) 51
    • 3) 68
    • 4) 85
    • Discussion in forum
      Answer : 2) 51
      Solution : Let the total number of men to be engaged be x.
      More length, More labours (Direct Proportion)
      Less days, More labours (Indirect Proportion)
      More hours per day, Less labours (Indirect Proportion)
      Length       26 : 39 Days       6 : 18 Hours per day 9 : 8 :: 17 : x
      => (26 * 6 * 9 * x) = (39 * 18 * 8 * 17)
      => x = (39 * 18 * 8 * 17)/(26 * 6 * 9)
      => x = 68
      Number of more labours = (68 - 17) = 51








      discussion


      Answer : 2) 51

    • ( 5 ) A wheel rotates 10 times every minute and moves 20 cm during each rotation. How many ems does the wheel move in 1 hour?

    • 1) 20000
    • 2) 14000
    • 3) 23000
    • 4) 12000
    • Discussion in forum
      Answer : 4) 12000
      Solution : Number of wheel moves in 1 hour = 10 * 60 = 600
      distance moved = 600 * 200 = 12000








      discussion


      Answer : 4) 12000

    • ( 6 ) 10 boys, working 6 hours a day can complete a work in 18 days. How many hours a day must 15 boys work to complete the same work in 12 days?

    • 1) 6
    • 2) 10
    • 3) 12
    • 4) 15
    • Discussion in forum
      Answer : 1) 6
      Solution : Let the required number of hours per day be x.
      More boys, Less hours per day (Indirect Proportion)
      Less days, more hours per day (Indirect Proportion)
      Boys 15 : 10 Days 12 : 18 :: 6 : x
      => 15 * 12 * x = 10 * 18 * 6
      => x = (10 * 18 * 6)/ (15 * 12)
      => x = 6








      discussion


      Answer : 1) 6

    • ( 7 ) If forty lamps can be lighted 5 hours per day for 10 days for Rs. 21.25,then the number of lamps which can be lighted 4 hours daily for 30 days for Rs. 76.50, is :

    • 1) 100
    • 2) 50
    • 3) 60
    • 4) 150
    • Discussion in forum
      Answer : 3) 60
      Solution :
      Hrs/Day   4 : 5 Money 21.25 : 76.50 Days     30 : 10 : : 40 : x
      4 * 21.25 * 30 * x = 5 * 76.50 * 10 * 40
      so x = 60








      discussion


      Answer : 3) 60

    • ( 8 ) A current pole 12 m high casts a shadow of length 18 m. The height of the tower, which casts a shadow of length 30 m under similar conditions will be:

    • 1) 10 m
    • 2) 20 m
    • 3) 17.6 m
    • 4) 21.25 m
    • Discussion in forum
      Answer : 2) 20 m
      Solution : Let the height of the tower x metres.
      Less lengthy shadow, Less in the height (Direct Proportion)
      18 : 30 :: 12 : x
      18 * x = 12 * 30
      x = 12 * 30/18
      x = 20








      discussion


      Answer : 2) 20 m

    • ( 9 ) If 10 men can crop a field in 8 days, then 8 men will crop the same field in :

    • 1) 5 days
    • 2) 4 days
    • 3) 20 days
    • 4) 10 days
    • Discussion in forum
      Answer : 4) 10 days
      Solution : 8 : 10 :: 8 : x or 8x = 10 * 8
      or x = 10.
      Required number of days 10.








      discussion


      Answer : 4) 10 days

    • ( 10 ) If p men, working p hours per day, can do p units of work in p days, then q men, working q hoyrs per day would be able to complete how many units of work in q days ?

    • 1) p2/q3
    • 2) p3/q2
    • 3) q2/p3
    • 4) q3/p2
    • Discussion in forum
      Answer : 4) q3/p2
      Solution : Let the required number of units of work be x.
      More men, more work (Direct Proportion)
      more working hours, more work (Direct Proportion)
      more days, more work (Direct Proportion)
      Men       p : q Hours per day p : q Days       p : q : : p : x
      ∴ (p * p * p * x) = (q * q * q * p)
      => x = q3/p2.








      discussion


      Answer : 4) q3/p2





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