If a spiral notebook cost $15, a 20% discount would reduce the price by 20/100 *15 = $<<15*0.2=3>>3
At a 20% discount, the buying price of a spiral notebook book is $15-$3= $<<15-3=12>>12
At the same discount, a personal planner cost would reduce by 20/100 * $10 = $<<20/100*10=2>>2
The new buying price of a personal planner will be $10-$2 =$<<10-2=8>>8
To buy four spiral notebooks at a 20% discount, you'll pay 4*$12 = $<<4*12=48>>48
At the same time discount, you'll buy eight personal planners at a cost pf 8*$8 = <<8*8=64>>64
In total, to buy eight personal planners and four spiral notebooks, you'd have to pay $64+$48 = $112
#### 112