Page 275 - Math Smart - 7

d) Mass of protein, fats and fibre in 100 g of beans = 7g + 1g + 6.2g = 14.2 g
14.2
= 14.2% of the beans is protein, fats or fibre.
100
Mass of beans that is not protein, fats or fibre = 100 g - 14.2 g = 85.8 g

So, = 85.8% of the beans is not protein, fats or fibre.
100

Check My
Understanding

O What percentage of each large square is shaded?

a) d)
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O 87% of the seats at a football match are occupied. What percentage of the seats are not occupied?
@ Sally spent 25% of her weekly pocket money during the week. She spent 45% of her weekly pocket
money over the weekend and saved the rest. What percentage of her weekly pocket money does she

save?
O 75 of the 100 balls in a box are red and the rest are blue. What percentage of the balls is red?

12.1.2 Converting between
percentages and fractions

You have seen how a percentage can be easily expressed as a fraction with a
denominator of 100. Let us convert percentages to fractions in its simplest form.

Example 3

Express 40% as a fraction in its simplest form.
Solution
40% = ^
A percentage is a fraction
_ 40-r20
" 100T20 with a denominator of
- 2 100.
5
On a calculator, use the % key and the equal sign. Enter:
The display gives the answer [Ti [Ti [iii^ rn R
5'