Linda bought 10 novels of the same kind during the Mother's Day Sale. Natalie bought 2 of the same novels. Natalie also bought 5 coins at $2.90 each. Altogether, she spent $1.70 more than Linda. What was the amount Natalie spent?
Amount that Natalie spent on 5 coins
= 5 x 2.90
= $14.50

Let the cost of each novel be 1 u. 

Amount that Linda spent = 10 u

Amount that Natalie spent =  2 u + 14.50

Natalie spent $1.70 more than Linda.  If Linda spent another $1.70, she would spend the same amount as Natalie.

10 u + 1.70 = 2 u + 14.50
10 u - 2 u = 14.50 - 1.70
8 u = 12.80

1 u = 12.80 ÷ 8 = 1.60

Cost of each novel
= 1 u
= $1.60

Amount that Natalie spent
= 2 x 1.60 + 14.50
= 3.20 + 14.50
= $17.70

Answer(s): $17.70