The outside distance around the trunk of a large tree is measured as $5.00\,\text{m}$. One year later, a second measurement gives $5.02\,\text{m}$.
(a)[2]
If the circumferences recorded each year make an arithmetic progression, determine the circumference $20$ years after the initial measurement.
(b)[3]
If the yearly circumferences are instead assumed to form a geometric progression, determine the circumference $20$ years after the first measurement.
Worked solution & mark scheme
This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Use the arithmetic-sequence expression $5.00+20\times0.02$ or $5.02+19\times0.02$.” …