Tables And Graphs - Class 8 Mathematics Revision Notes

Tables And Graphs

Worked Exercise

1. Kariet ole Koria started from his home at 8.00a.m to Narok, a distance of 140km. After covering 80 km he rested for 30 minutes before proceeding with the journey.
   
   Calculate Koinet Ole Koria’s average speed for the whole journey in km/h
   
   Working
   Total distance = 140km
   Total time taken = 3 hrs
   Average speed = ^{Distance covered}/_{Total time taken}
   = ¹⁴⁰/_3.5
   = 40 km/h
   The correct answer is D (40 km/h)
2. The graph shown below represents Kabugi’s journey from Nairobi to Bungoma and back.
   
   What was his average speed for the whole journey?
   
   1. 53 km/h
   2. 50 km/h
   3. 100 km/h
   4. 106 km/h
      Working
      Total distance;
      Nairobi – Bungoma = 400km
      Bungoma - Nairobi = 400km
      Total = 800km
      Total time = 8 hours
      Average Speed = ^{Total distance covered}/_{Total time taken}
      = ( 800 ÷ 8)km/h
      = 100km/hr
      The correct answer is C (100km/h)
3. The pie chart shown below shows how Erastus spent his salary. How much did he spend on food and transport if he saved sh2500
   
   1. Sh 4500
   2. Sh 12000
   3. Sh 2500
   4. Sh 5000
      Working
      The angle representing savings
      {360 - (78 + 72 + 54 + 81) } = 75º
      If 75º = Sh 2500
      360º= ?
      = (^{360 x 2500)}/₇₅
      = Sh 12000
      Food and transport = 54 + 81
      = 135
      (135 x 12000) Sh
           360
      = Sh 4500
4. Eleven standard 4 pupils of St. John school scored a test as follows 95, 50, 48, 63, 58, 75, 48, 44, 58, 84, 48. Which of the following a arrangements shows the mean, mode and median of the marks?
   1. 58, 61, 48
   2. 61, 48, 58
   3. 61, 58, 48
   4. 48, 58, 61
      Working
      Mean = Total marks    
                   No of children
      = 671 ÷ 11
      = 61 marks
      Median: 44, 48, 48, 48, 50, 58, 58, 63, 75, 84, 95
      The number in the middle is 58.
      Mode: is the number appearing many times.
      The correct answer is B (61, 58, 48)
5. Njoroge scored as follow in a test.
   70, 55, 80, 50, 55
   What is his mean score?
   1. 55
   2. 62 
   3. 65
   4. 80
      Working
      Mean = (70 + 55 + 80 + 55) ÷ 5