PSLE
Billy and Andy were paid a total of $1820 for a job they did. Andy was paid $1360 less than Billy.

1. How much was Andy paid for the job?
2. Billy and Andy were paid based on the number of days they worked. Billy worked 3 times as many days as Andy. Billy was paid $20 more than Andy per day. How many days did Billy work? 

(a)
Amount that Andy was paid = 1 u
Amount that Billy was paid = 1 u + 1360

Total amount paid
= 1 u + 1 u + 1360
= 2 u + 1360

2 u + 1360 = 1820
2 u = 1820 - 1360
2 u = 460

1 u = 460 ÷ 2 = 230

Amount that Andy was paid
= 1 u
= $230

(b)
Amount that Billy was paid
= 1 u + 1360
= 230 + 1360
= $1590

Billy worked 3 times as many days as Andy.

3 sets of Billy's salary = $1590

1 set of Billy's salary
= 1590 ÷ 3
= $530

1 set of Andy's salary = $230

Difference between each set of Billy's and Andy's salaries
= 530 - 230
= $300

Number of days in 1 set
= 300 ÷ 20
= 15

Number of days that Billy worked
= 3 x 15
= 45

Answer(s): (a) $230; (b) 45