Test 2

• Important symbols


  • E is a member of
  • $ is not a member of
  • n(A) the number of elements in set A
  • n
  • DCU Q
  • E
  • A'
  • union "OR"
  • intersection "AND"
  • is a subset of "BELONGS TO
  • empty set
  • universal set or background set
  • complement of set A "Not A"
• Using Prime Factor Form and a Venn Diagram to find the HCF of 24 and 60


  1. Write 24 and 60 in prime factor form

  2. Draw a Venn Diagram with a set for the prime factors of 24 and a set for the prime factors of 60

  3. HCF Interaction
• Compound Interest


  A = P (1+r) n-years
• Compound Interest


  • $1000 x 180/25 3 years 2-25%
• Percentage increase


  The decimal multiplier method
• A length is increased by 20%

  The new total length is 120% of the original length
• If the original length was 330cm, the new total length is 396cm
• A house originally bought for £250,000

  Increased in value by 9% over 5 years, so it is now worth £272,500
• Percentage decrease


  The decimal multiplier method
• A length is decreased by 20%


  The new total length is 80% of the original length
• If the original length was 330cm, the new total length is 264cm
• Percentage increase/decrease/change


  Actual change x 100% / original
• Percentage loss


  • A car bought for £25000, sold for £15000 is a 40% loss
• Percentage profit


  • Jeans bought for £20, sold for £35 is a 75% profit
• Mean


  How much you would have if you could divide the data up evenly
• Mode


  The most frequently occurring piece of data
• Median


  The middle piece of data when they are arranged in order of size
• Quartiles


  • Q1 is the lower quartile, 25% of the data will lie below this value
  • Q2 is the median, 50% of the data will lie below this value
  • Q3 is the upper quartile, 75% of the data will lie below this value
  • The INTERQUARTILE RANGE is equal to Q3 - Q1, and therefore is the range of the middle 50% of the data set