PSLE
Oliver and Mark were paid a total of $2370 for a job they did. Mark was paid $1290 less than Oliver.

1. How much was Mark paid for the job?
2. Oliver and Mark were paid based on the number of days they worked. Oliver worked 3 times as many days as Mark. Oliver was paid $10 more than Mark per day. How many days did Oliver work? 

(a)
Amount that Mark was paid = 1 u
Amount that Oliver was paid = 1 u + 1290

Total amount paid
= 1 u + 1 u + 1290
= 2 u + 1290

2 u + 1290 = 2370
2 u = 2370 - 1290
2 u = 1080

1 u = 1080 ÷ 2 = 540

Amount that Mark was paid
= 1 u
= $540

(b)
Amount that Oliver was paid
= 1 u + 1290
= 540 + 1290
= $1830

Oliver worked 3 times as many days as Mark.

3 sets of Oliver's salary = $1830

1 set of Oliver's salary
= 1830 ÷ 3
= $610

1 set of Mark's salary = $540

Difference between each set of Oliver's and Mark's salaries
= 610 - 540
= $70

Number of days in 1 set
= 70 ÷ 10
= 7

Number of days that Oliver worked
= 3 x 7
= 21

Answer(s): (a) $540; (b) 21