Answer:
Marco saves $35 more than Nancy.
Step-by-step explanation:
Nancy saves $2 per week. After 10 weeks she will have saved 2 * 10 = $20.
Marco saves $1 the first week, $2 the second week, and $3 the third week and so on. This means for 10 weeks he will save 1+2+3+4+5+6+7+8+9+10=$55.
Marco saves $35 more than Nancy.