1. (a)
30 km/h
(b)
40 cm2
(c)
55.8 cm
(d)
300 cm3
(e)
5 m
2. (a)
y = 2xz
(f)
(g)
3. (a)
20 − a
8a
4(20 − a)
4(20 − a) + 8a = 136
a = 14
There are 6 children.