A spiral notebook costs $15, and a personal planner costs $10. How much would it cost in total to buy 4 spiral notebooks and 8 personal planners at a 20% discount? Let's be accurate as possible.
If a spiral notebook cost $15, a 20% discount would reduce the price by 20 / 100 * 15 = $3. At a 20% discount, the buying price of a spiral notebook book is $15 - $3 = $12. At the same discount, a personal planner cost would reduce by 20 / 100 * $10 = $2. The new buying price of a personal planner will be $10 - $2 = $8. To buy four spiral notebooks at a 20% discount, you'll pay 4 * $12 = $48. At the same time discount, you'll buy eight personal planners at a cost pf 8 * $8 = 64. In total, to buy eight personal planners and four spiral notebooks, you'd have to pay $64 + $48 = $112.
The answer: 112.