A store has the following arrangements for purchasing a gas stove.

Plan A
Cash Price $5 559

Plan B
Down-payment $1 000
6 instalments at $815 per month

Plan C
Down-payment $0
24 instalments at $275 per month

(a) Aunty Merle has a shop and needs a stove. What is the best hire purchase plan she can chose in terms of lowest interest on the cash price?

(b) Aunty Merle chose to use Plan C for her purchase.
What are two reasons she would choose plan C?