Pierre received $1 from his aunt in the 1st week of school and $8 in the 2nd week. Each week, he receives $7 more than the week before.
- How much money did he received in the 18th week?
- In which week did he receive $15?
(a)
Amount that Pierre received on 1st Week = $1
Amount that Pierre received on 2nd Week = $17
Formula:
Amount received each week = 1 + (Week number - 1) x $7
Amount received on Week 18
= 1 + (18 - 1) x 7
= 1 + 17 x 7
= 1 + 119
= $120
(b)
Week number that Pierre received $15
= [(15 - 1) ÷ 7] + 1
= (14 ÷ 7) + 1
= 2 + 1
= 3
Answer(s): (a) $120; (b) 3