Need help with this question grade 12 math 4 and 5 grade 12

Awindow washer cleans 42 windows in 2 hours. at this rate, how many windows did he clean in 180 minutes.

If the tip varies directly with the number of guest which equation represents between the tip,t, and the number of guest,g?

Harry owes the bank money. to repay his debt, he paid $150 back to the bank each month. after 10 months, his remaining debt was $6900. what was the original amount of harry's debt? how long did it take harry to pay back his entire debt?