Page 75 - Mathematics

Chapter summary

1. A ratio is a comparison between two or more quantities which are in the
same unit and can be simplified as a fraction.
2. A ratio can be expressed as a fraction, using colon or in words.
3. A proportion is a statement that two ratios are equal. Tanzania Institute of Education
4. In general, a proportion describes a part, a share or a number considered
in comparison to a whole.

Revision exercise 4

1. Express each of the following ratios as percentages.
1 1
(a) 1: 20 (c) 49 :500 (e) 1 : 2 4
2
3 1
(b) 1: 200 (d) :
82
2. Express each of the following percentages as ratios in their lowest form.
1
(a) 72% (c) 0.25% (e) 8 %
1 3
(b) 27 % (d) 28%
2
3. An entrepreneur has a capital of 1,520,000 Tanzanian shillings. If she
increases it by 20%, how much will she have?
4. Three relatives share 180,950 Tanzanian shillings so that the first receives
twice as much as the second, and the second receives twice as much as
the third. How much does the first receive?
5. Divide 270 kg in the ratio 1: 4:5.
6. Divide 360° in the ratio 1: 2:5:7.
7. Calcium and chlorine combine in the ratio 9:16. Calculate the mass of
chlorine that will combine with 5 grams of calcium.
8. Ashura is making a juice containing water and lemon juice. She needs 3
cups of water for every cup of lemon juice. If she wants to make 10 cups
of the juice, how many cups of water and lemon juice does she need?
9. Two numbers are in the ratio of 3:5. Find the larger number if the smaller
number is 36.
10. Three numbers are in the ratio of 3: 4:5. Find the largest number if their
sum is 48. Mathematics Form One
11. Ambele weighs 65.8 kg. He wants to reduce his mass so that the ratio
of his present mass to his new mass is 8:7. Find his new mass.

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25/10/2024 09:51:20
Mathematics form 1.indd 69
Mathematics form 1.indd 69 25/10/2024 09:51:20