John received $1 from his mother in the 1st week of school and $5 in the 2nd week. Each week, he receives $4 more than the week before.
- How much money did he received in the 5th week?
- In which week did he receive $17?
(a)
Amount that John received on 1st Week = $1
Amount that John received on 2nd Week = $4
Formula:
Amount received each week = 1 + (Week number - 1) x $4
Amount received on Week 5
= 1 + (5 - 1) x 4
= 1 + 4 x 4
= 1 + 16
= $17
(b)
Week number that John received $17
= [(17 - 1) ÷ 4] + 1
= (16 ÷ 4) + 1
= 4 + 1
= 5
Answer(s): (a) $17; (b) 5