Page 162 - MATHEMATICS COURSE FOR SECONDARY SCHOOLS BOOK 2

6 An anaconda measures 1.69 cm in a picture. The stated scale is 1 cm to 5 m. What is the actual length of the anaconda?
7 The scale of a map of a country is 1 cm to 50 km. The straight-line distance between two towns is measured as 2.7 cm on the map. What is the actual distance between the two towns?
RATIO
Revision exercise 12
1EXMAeaMsuPreLaEnd4write down the length of each line segment.
The directions on a label reads ‘Mix 3 parts of
How much detergent is needed to mix with 137 ml of water?
3 Copy these lines onto a sheet of paper. mixtuBries.ect each of the lines.
(a) A
Please detergent with 5 parts of water?
Sox ie
x
5( x + 960) = 8 (x)
supply this artwork
(c)
Use a ruler and a protractor to draw each
(a) (b)
. ..
5 x + 4800 = 8x
4800 = 8x – 5x
B
D : 1375 = 3 : 5
D/1375 = 3 P5R
C
4800 = 3x 3x = 4800
The volume of detergent : the volume of (bw)ater=3:5 Q
of these angles.
(a) 􏰀ABC = 35°
Hence, 1375 ml of water is needed to make the
4
And
5
Measure each of these angles.
(a) A (b)
EXAMPLE 5
Q
The monthly rent of an apartm(ce)nt increased in the
BP
$960 more. What was the original rent?
ST
ratio 8 : 5. As a result the apartment renter paid
Let the original rent = $ x y (a) (b)
Please supply this artwork
So the new rent = $ (x + 960)
the new rent : the original rent
= 8 : 5 (x+960) = 85
z
Please supply this artwork
35 􏰂 1375
= 3 􏰂 275 = 825
(c) 􏰀PQR = 257°
Hence, the original rent was $1600.
Please supply this (b) artwork
(c) N
M
386
156
So
.. .
(b) 􏰀KLMx ==11660°0 (d) 􏰀XYZ = 98°
EXfiEndRtCheISE7.2 68o
value of z, y
giving z
reaThsoensd.irection on a label reads ‘Mix 3 parts
7
8
the volume of detergent
= 5 : 3
a reason in each case.
(a)A picture measuring 8(.b5) cm by 4.5 cm is
(a) AB = 6.5 cm
(b) KL = 7.8 cm
2
So W : 825
= 5 : 3
Please supply this artwork
(c) RS = 9.4 cm
3o
ie
W/825 = 5
W = 35 􏰂 825
o 29
. . .
dimensions of the enlarged picture.
x
D =
6 Given that x is twice y,
Please supply this artwork
Hence, 825 ml of detergent is needed to make the
1
of milk with 7 parts of cream soda?
mixture.
S
(a) How many degrees are there in: (i) three-quarters of a revolution
How much water is needed to mix with 975 ml of detergent?
KL
with 525 ml of cream soda?
The volume of water :
(b) How much cream soda is needed to
2 Draw each of these line segments.
mix with 90 ml of milk?
(d) XY = 10.3 cm
= 5 􏰂 275 = 1375
enlarged in the ratio 7:5. Find the134
p
(a) How much milk is needed to mix
(ii) two and a half right angles?
(b) How many right angles are there in one and three-quarters of a turn?
Calculate the value of each letter, stating
x