Answer:
7
Explanation:
After the quarter is added, the amount totals $2.10. This consists of groups of two coins, a nickel and a quarter. Each such group is worth $.30, so there must be $2.10/$0.30 = 7 groups.
Emma has 7 nickels, worth $0.35. After her father gave her the quarter, she also had 7 quarters. Before that, she had 6 quarters worth $1.50.