Year 10 Interactive Maths - Second Edition

Problem Solving Unit

Problem 7.1  Best Subject

Tina Tucker had tests in four subjects and obtained the following marks:

• Mathematics - 54 out of 60
• Science - 28 out of 40
• Information Technology - 21 out of 30
• Art - 13 out of 20

a.  Name Tina's best subject. What percentage mark did she achieve in this subject?
b.  Name Tina's worst subject. What percentage mark did she achieve in this subject?
c.  Calculate Tina's average mark as a percentage.

Problem 7.2  Percentage Error

3.
a.  Obtain a set of measurements of heights of the students in your class to the nearest centimetre.
b.  Find the average height.
c.  Rewrite the set of the measurement of height, approximating all measurements. For example, a height of 142 can be approximated to 140 cm; whereas, a height of 148 cm can be approximated to 150 cm.
d.  Find the new average height.
e.  Find the error in the average height; and hence calculate the percentage error.