Perry received $3 from his mother in the 1st week of school and $5 in the 2nd week. Each week, he receives $2 more than the week before.
- How much money did he received in the 9th week?
- In which week did he receive $29?
(a)
Amount that Perry received on 1st Week = $3
Amount that Perry received on 2nd Week = $8
Formula:
Amount received each week = 3 + (Week number - 1) x $2
Amount received on Week 9
= 3 + (9 - 1) x 2
= 3 + 8 x 2
= 3 + 16
= $19
(b)
Week number that Perry received $29
= [(29 - 3) ÷ 2] + 1
= (26 ÷ 2) + 1
= 13 + 1
= 14
Answer(s): (a) $19; (b) 14