Answer:
11 cans of cat food...........
Step-by-step explanation:
£0.79 x 11 = £8.69
£8.69 - £2 = 6.69
This is exponential decay which can be expressed as:
y=ab^t, y=final value, a=initial value, b=rate, t=time
In this case a=25000, r=(100-20)/100=0.8 so
y=25000(0.8^t), so in 4.5 years...
y=25000(0.8^4.5)
y≈$9158.93 (to nearest cent)
