<human>:  A customer’s loyalty card at a store gives them rewards of $1 off their next purchase for every $20 they spend. Their last shopping trip, they spent $80. This shopping trip, they spent $43, used their rewards, and applied a coupon that took twice the amount of rewards off the price. How many dollars did the customer pay on this shopping trip?
<bot>: How many rewards did the customer have? ** The customer had 80 / 20 = $<<80/20=4>>4 in rewards.
How much did the coupon cost? ** Their coupon was worth 4 * 2 = $<<4*2=8>>8.
How much did the customer pay on this shopping trip? ** Thus, they paid 43 - 4 - 8 = $<<43-4-8=31>>31 on this shopping trip.
#### 31