Tommy received $4 from his mother in the 1st week of school and $6 in the 2nd week. Each week, he receives $2 more than the week before.
- How much money did he received in the 20th week?
- In which week did he receive $28?
(a)
Amount that Tommy received on 1st Week = $4
Amount that Tommy received on 2nd Week = $19
Formula:
Amount received each week = 4 + (Week number - 1) x $2
Amount received on Week 20
= 4 + (20 - 1) x 2
= 4 + 19 x 2
= 4 + 38
= $42
(b)
Week number that Tommy received $28
= [(28 - 4) ÷ 2] + 1
= (24 ÷ 2) + 1
= 12 + 1
= 13
Answer(s): (a) $42; (b) 13