PSLE
Oscar and Owen were paid a total of $2400 for a job they did. Owen was paid $840 less than Oscar.

1. How much was Owen paid for the job?
2. Oscar and Owen were paid based on the number of days they worked. Oscar worked 2 times as many days as Owen. Oscar was paid $15 more than Owen per day. How many days did Oscar work? 

(a)
Amount that Owen was paid = 1 u
Amount that Oscar was paid = 1 u + 840

Total amount paid
= 1 u + 1 u + 840
= 2 u + 840

2 u + 840 = 2400
2 u = 2400 - 840
2 u = 1560

1 u = 1560 ÷ 2 = 780

Amount that Owen was paid
= 1 u
= $780

(b)
Amount that Oscar was paid
= 1 u + 840
= 780 + 840
= $1620

Oscar worked 2 times as many days as Owen.

2 sets of Oscar's salary = $1620

1 set of Oscar's salary
= 1620 ÷ 2
= $810

1 set of Owen's salary = $780

Difference between each set of Oscar's and Owen's salaries
= 810 - 780
= $30

Number of days in 1 set
= 30 ÷ 15
= 2

Number of days that Oscar worked
= 2 x 2
= 4

Answer(s): (a) $780; (b) 4