Gillian received $20 more pocket money than Cathy each month. Both of them spent $120 per month and saved the rest. After a few months, Gillian saved $1600 but Cathy only saved $1200.

1. What was Gillian's monthly pocket money?
2. Cathy wanted to save a total of $2220. How many more months did she need in order to save this amount?

(a)
Total amount that Gillian saved more than Cathy
= 1600 - 1200
= $400

Number of months taken for each of them to save their amounts
= 400 ÷ 20
= 20

Amount that Gillian saved each month
= 1600 ÷ 20
= $80

Gillian's monthly pocket money
= 80 + 120
= $200

(b)
Cathy's monthly pocket money
= 200 - 20
= $180

Amount that Cathy saved each month
= 180 - 120
= $60

Remaining amount that Cathy needed to save
= 2220 - 1200
= $1020

Number of more months that Cathy needed to save the remaining $1020
= 1020 ÷ 60
= 17

Answer(s): (a) $200; (b) 17