Sean received $2 from his mother in the 1st week of school and $9 in the 2nd week. Each week, he receives $7 more than the week before.
- How much money did he received in the 20th week?
- In which week did he receive $23?
(a)
Amount that Sean received on 1st Week = $2
Amount that Sean received on 2nd Week = $19
Formula:
Amount received each week = 2 + (Week number - 1) x $7
Amount received on Week 20
= 2 + (20 - 1) x 7
= 2 + 19 x 7
= 2 + 133
= $135
(b)
Week number that Sean received $23
= [(23 - 2) ÷ 7] + 1
= (21 ÷ 7) + 1
= 3 + 1
= 4
Answer(s): (a) $135; (b) 4