18.85 I hope this helps you :)
450 chairs total
20 chairs per row
15 rows already set up
15×20=300
300 chairs already up
450-300=150
150 chairs left to set up
Use this method, length x width x height
Jack spends 15% on sweets each week and 35% on magazines. His total spendings(15%+35%=50%)equals 50%.Savings is 100% - 50%= 50%.So, if jack gets $100 each week, he spends $15 on sweets, $35 on magazines, and $50 goes towards savings. Hope this helps!
