Esther was saving money to buy pens. She saved $3 every 5 days. After saving for 65 days, she went to buy pens that were on sale.
- What was the most number of pens she could buy?
- Esther wanted to buy 37 pens. How much more did she need to save?
(a)
Number of sets of 5 days
= 65 ÷ 5
= 13
Amount that Esther saved in 65 days
= 13 x 3
= $39
Maximum number of sets of 8 pens that Esther could buy
= 39 ÷ 10
= 3 r $9
Remaining amount left after buying sets of 8 pens = $9
Maximum number of sets of 4 pens that Esther could buy with $9
= 9 ÷ 6
= 1 r $3
Remaining amount left after buying sets of 4 pens = $3
Maximum number of pens that Esther could buy with $3
= 3 ÷ 3
= 1
Most number of pens that Esther could buy
= 3 x 8 + 1 x 4 + 1
= 24 + 4 + 1
= 29
(b)
Number of sets of 8 pens that Esther could buy
= 37 ÷ 8
= 4 r 5
Number of sets of 4 pens that Esther could buy
= 5 ÷ 4
= 1 r 1
Number of individual pens that Esther could buy = 1
Amount that Esther needed to buy 37 pens
= 4 x 10 + 1 x 6 + 3
= 40 + 6 + 3
= $49
Amount that Esther needed to save more
= 49 - 39
= $10
Answer(s): (a) 29; (b) $10
