Question

Choy has $25 in his lunch account at school. He spends $3 each day to eat in the cafeteria. What is Choy's lunch account balance after two weeks of buying his lunch in the cafeteria?

Answer 1

Answer: −$5

Explanation:

Suppose there are 5 school days in 1 week

Then for 2 weeks we have 2×5=10 days

At $3 for each day this gives a total spent as: 10×$3=$30

The amount in the account is $25

So the account at the end of this period has 'deposit - expense'.

which is  $25−$30=−$5

The negative $5 means that Choy has borrowed −$5

So he is in debt.