What type of scientist studies have bacteria are affected by antibiotics?

A=P(1-r)n

Where P= principal

r= rate of depreciation

n=number of terms (years)

Compare with compound interest: A=P(1+r)n

Example : a TV originally worth $1250 depreciates at 6% pa.

1. What is it worth after 7 years?

A=P(1-r)n

P=$1250

r=6% =0.06

n=7years

A=1250 (1-0.06)7

A=1250 (0.94)7

A=1250 x 0.648

A=$810.60

The TV is worth $810.60 after 7 years.

1. By how much has the TV depreciated over this time?

Original value: $1250

Current value: $810.60

Depreciation = $1250-$810.60

=$439.40

The TV has depreciated by $439.40 in 7 years.

Ex 4j

1. A=P(1-r)n

P=$2800

r=25% =0.25

n=3years