<human>:  A mother goes shopping. She buys cocoa at $4.20, laundry at $9.45 and a package of pasta at $1.3<human>: Continue.
<bot>: How much does the mother spend in total? ** The total shopping cost is $4.2 + $9.45 + $1.35 = $<<4.2+9.45+1.35=15>>15.
How much change does the cashier give back? ** The cashier gives back $20 - 1$5 = $<<20-15=5>>5.
#### 5