Page 74 - Mathematics
P. 74
Cross-multiplication gives, 7. A powdery mixture is made up of
10y = 1 400× powders A and B in the ratio 5: 4.
1 400× If 72 kg of this mixture are required,
y =
10 how much of each type should be
40= used?
Therefore, 40 drivers out of 400 have 8. An alloy is made up of metals x and
attended the driving safety seminar. y in the ratio 2.4:1 by mass. How
much mass of y is required if 8 kg
Exercise 4.2 of x is used to make the alloy?
9. If the ratio of lead to tin in a solder
Tanzania Institute of Education
1. Divide each of the following in the
given ratios. is 1.8:1, how much mass of tin is
(a)100 in ratio 7 :3 needed when 90 kg of lead is used?
(b) 75 in the ratio 3: 2 10. A line segment AB, which is 24 cm
(c) 16 in the ratio 3:3: 2 long, is divided at a point P (between
1 A and B) in the ratio 7:5. Find the
(d) in the ratio 4:1
2 lengths of AP and PB.
2. If 800 kilograms of rice are shared 11. The volumes of two tanks are in the
between two families in the ratio ratio 2:5. If the volume of the first
3: 2, how much does each family tank is 2,600 litres, find the total
get? volume of the two tanks.
3. Divide 60,000 Tanzanian shillings 12. A real horse is 1.8 m high. The statue
among Juma, Ali, and Aisha in the of the horse is 3 m high. What is the
ratio 5:3: 2. ratio of the height of the horse to the
4. Musa, Josephine, Mary, and Kato height of the statue?
have 300, 100, 500, and 600 shares 13. Jason has 500, 200, and 100
in a cooperative shop, respectively. Tanzanian shilling coins. The ratio
Divide 150,000 Tanzanian shillings of the total amount of these coins
among them in the ratio of their is 2:3:5, and the total amount is
shares. 780,000 Tanzanian shillings. Find
Mathematics Form One 6. Divide 28.6 kg of meat among four 14. Find the fourth proportional of 6, 9,
5. Magnesium combines with oxygen
the number of the coins of each kind.
in the ratio 3: 2 by mass to form
a new substance. What mass of
and 12.
magnesium will be needed to
15 Find the third proportional of 2n
2
combine with 1.4 kg of oxygen?
2
and 3.n
families in the ratio 4:5:6:7.
68
25/10/2024 09:51:20
Mathematics form 1.indd 68
Mathematics form 1.indd 68 25/10/2024 09:51:20
