Hilda was saving money to buy pens. She saved $5 every 7 days. After saving for 49 days, she went to buy pens that were on sale.
- What was the most number of pens she could buy?
- Hilda wanted to buy 32 pens. How much more did she need to save?
(a)
Number of sets of 7 days
= 49 ÷ 7
= 7
Amount that Hilda saved in 49 days
= 7 x 5
= $35
Maximum number of sets of 9 pens that Hilda could buy
= 35 ÷ 12
= 2 r $11
Remaining amount left after buying sets of 9 pens = $11
Maximum number of sets of 5 pens that Hilda could buy with $11
= 11 ÷ 7
= 1 r $4
Remaining amount left after buying sets of 5 pens = $4
Maximum number of pens that Hilda could buy with $4
= 4 ÷ 4
= 1
Most number of pens that Hilda could buy
= 2 x 9 + 1 x 5 + 1
= 18 + 5 + 1
= 24
(b)
Number of sets of 9 pens that Hilda could buy
= 32 ÷ 9
= 3 r 5
Number of sets of 5 pens that Hilda could buy
= 5 ÷ 5
= 1 r 0
Amount that Hilda needed to buy 32 pens
= 3 x 12 + 1 x 7
= 36 + 7
= $43
Amount that Hilda needed to save more
= 43 - 35
= $8
Answer(s): (a) 24; (b) $8
