C is the rigth answer because all the other three has two x values in common. :)
8.40/3 = £2.80 each
...............
1.
The edge lengths of a triangle are inversely proportional to 2,3 and 4.
The actual proportions of the lengths are then
12(1/2:1/3:1/4)=6:4:3
The longest side
= 39* (6/(6+4+3)
= 39*6/13
=18
2. 63 breads : 35 kg flour
is the same as
54 breads : x kg flour
Cross multiply and get
x=54*35/63=30
30 kg of flour are needed to make 54 breads.
