Question

In a project, Mr Tung's daily wage was $100 more than Mr Pang's. Although Mr Tung worked 3 days less than Mr Pang, both of them earned $3600. Find the number of days Mr Tung worked in the project.

Answer 1

Find x, the days Mr. Tung has worked.
Mr. Tung's daily wage is (3600/x).
Mr. Pang's daily wage is (3600/x)-100.
Mr. Pang worked (x+3) days.

Therefore:
3600 = (3600/x -100)(x+3)

Multiply by x/100:
36x = (36-x)(3+x)

Expand and rearrange into quadratic form. Then find the quadratic roots. At least one root will be the number of days Mr. Tung has worked.