How many $10 Notes

 1 .Does Mrs Jones have enough money now: $167 for 13 students Yes she has enough. Leftover $7 2 .Does Mrs Jones have enough money now: $203 for 41 students no she doesn't Need 20 ten s. 3 .Does Mrs Jones have enough money now: $203 for 21 students no she doesn't Need 1 ten 4 .Does Mrs Jones have enough money now: $199 for 18 students yes she does Leftover $9 5 .Does Mrs Jones have enough money now: $167 for 17 students no she doesn't Need $1 ten