Answer: he earned $344 in all.
Step-by-step explanation:
When he does work outdoors he earns $12 an hour. This means that if he works outdoors for x hours, he would earn $12x
When he works indoors he earns $8 an hour. This means that if he works indoors for y hours, he would earn $8y.
Last month he worked 18 hours outdoors. This means that the total amount that he earned working outdoors is
12 × 18 = $216
He worked 16 hours indoors. This means that the total amount that he earned working indoors is
8 × 16 = $128
Total amount that he earned is
216 + 128 = $344
