Pierre received $3 from his father in the 1st week of school and $6 in the 2nd week. Each week, he receives $3 more than the week before.
- How much money did he received in the 5th week?
- In which week did he receive $18?
(a)
Amount that Pierre received on 1st Week = $3
Amount that Pierre received on 2nd Week = $4
Formula:
Amount received each week = 3 + (Week number - 1) x $3
Amount received on Week 5
= 3 + (5 - 1) x 3
= 3 + 4 x 3
= 3 + 12
= $15
(b)
Week number that Pierre received $18
= [(18 - 3) ÷ 3] + 1
= (15 ÷ 3) + 1
= 5 + 1
= 6
Answer(s): (a) $15; (b) 6