Similarity (Chapter 18) 379
5 Consider the followingsimilarsolids. Find the unknown length or volume:
ab
cd
6 Two solid wooden spheres have radiiacm and 3 acm respectively. If the smaller one has volume
250 cm^3 , find the volume of the larger one.
7 The surface areas of two similar cylinders are 6 cm^2 and 54 cm^2 respectively.
a If the larger cylinder has height 12 cm, find the height of the smaller one.
b If the volume of the smaller cylinder is 24 cm^3 , find the volume of the larger one.
8 Two similar cones have volumes 4 cm^3 and 108 cm^3 respectively. Find the surface area of the smaller
one if the larger has surface area 54 cm^2.
9 Two buckets are similar in shape. The smaller one is 30 cm tall and the larger
one is 45 cm tall.
Both have water in them to a depth equal to half of their heights. The volume
of water in the small bucket is 4400 cm^3.
a What is the scale factor in comparing the smaller bucket to the larger one?
b What is the volume of water in the larger bucket?
c The surface area of the water in the larger bucket is 630 cm^2. What is
the surface area of the water in the smaller bucket?
10 Two cylindrical containers have capacities 875 ml and
2240 ml respectively. Thin straws are placed in the
cylinders as shown.
These have length 10 cm and 16 cm respectively. Are
the cylinders similar? Give evidence to support your
answer.
3cm
6cm
10 cmC
VcmC 6cm
9cm
12 cmC VcmC
xcm
9cm
10 cmC
50 cmC
flat
10 cm
16 cm
11 Answer the questions of theOpening Problemon page 367.
6cm
27 cmC
64 cmC
xcm
IGCSE01
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Y:\HAESE\IGCSE01\IG01_18\379IGCSE01_18.CDR Friday, 7 November 2008 4:34:10 PM PETER