Sabrina was saving money to buy pens. She saved $4 every 5 days. After saving for 60 days, she went to buy pens that were on sale.
- What was the most number of pens she could buy?
- Sabrina wanted to buy 38 pens. How much more did she need to save?
(a)
Number of sets of 5 days
= 60 ÷ 5
= 12
Amount that Sabrina saved in 60 days
= 12 x 4
= $48
Maximum number of sets of 7 pens that Sabrina could buy
= 48 ÷ 10
= 4 r $8
Remaining amount left after buying sets of 7 pens = $8
Maximum number of sets of 3 pens that Sabrina could buy with $8
= 8 ÷ 5
= 1 r $3
Remaining amount left after buying sets of 3 pens = $3
Maximum number of pens that Sabrina could buy with $3
= 3 ÷ 3
= 1
Most number of pens that Sabrina could buy
= 4 x 7 + 1 x 3 + 1
= 28 + 3 + 1
= 32
(b)
Number of sets of 7 pens that Sabrina could buy
= 38 ÷ 7
= 5 r 3
Number of sets of 3 pens that Sabrina could buy
= 3 ÷ 3
= 1 r 0
Amount that Sabrina needed to buy 38 pens
= 5 x 10 + 1 x 5
= 50 + 5
= $55
Amount that Sabrina needed to save more
= 55 - 48
= $7
Answer(s): (a) 32; (b) $7