Barbara received $20 more pocket money than Kathy each month. Both of them spent $110 per month and saved the rest. After a few months, Barbara saved $1710 but Kathy only saved $1330.

1. What was Barbara's monthly pocket money?
2. Kathy wanted to save a total of $2100. How many more months did she need in order to save this amount?

(a)
Total amount that Barbara saved more than Kathy
= 1710 - 1330
= $380

Number of months taken for each of them to save their amounts
= 380 ÷ 20
= 19

Amount that Barbara saved each month
= 1710 ÷ 19
= $90

Barbara's monthly pocket money
= 90 + 110
= $200

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

Amount that Kathy saved each month
= 180 - 110
= $70

Remaining amount that Kathy needed to save
= 2100 - 1330
= $770

Number of more months that Kathy needed to save the remaining $770
= 770 ÷ 70
= 11

Answer(s): (a) $200; (b) 11