Write in column form and subtract

Molly, landy and jasmine are hairdressers. molly and landy have 678 hairpins altogether. landy and jasmine have 984 hairpins altogether. if molly has 3/5 as many hairpins as jasmine, how many hairpins does landy have? ​

Abag contain 72 red marbles and some green marbles. the green marbles are less than red marbles. how many are green marbles

In the figure on the rigth mxy =150 and mmn=30 what is m