PSLE
Simon and Luis were paid a total of $4640 for a job they did. Luis was paid $1600 less than Simon.

1. How much was Luis paid for the job?
2. Simon and Luis were paid based on the number of days they worked. Simon worked 2 times as many days as Luis. Simon was paid $4 more than Luis per day. How many days did Simon work? 

(a)
Amount that Luis was paid = 1 u
Amount that Simon was paid = 1 u + 1600

Total amount paid
= 1 u + 1 u + 1600
= 2 u + 1600

2 u + 1600 = 4640
2 u = 4640 - 1600
2 u = 3040

1 u = 3040 ÷ 2 = 1520

Amount that Luis was paid
= 1 u
= $1520

(b)
Amount that Simon was paid
= 1 u + 1600
= 1520 + 1600
= $3120

Simon worked 2 times as many days as Luis.

2 sets of Simon's salary = $3120

1 set of Simon's salary
= 3120 ÷ 2
= $1560

1 set of Luis's salary = $1520

Difference between each set of Simon's and Luis's salaries
= 1560 - 1520
= $40

Number of days in 1 set
= 40 ÷ 4
= 10

Number of days that Simon worked
= 2 x 10
= 20

Answer(s): (a) $1520; (b) 20