You can solve this using proportion.
5 = 4
7 = ?
7(4)/5= 5.6
7 cakes cost £5.6
£5.60
divide £4 by 5 to obtain the cost of 1 cake then multiply this value by 7 for the cost of 7 cakes
5 → £4
7 → £4 × [tex]\frac{7}{5}[/tex] = £5.60
