It's 149nickels because how much nickels equal $1.00, it's 20 nickels then multiply it by 7 which equal 140 nickels and 140 nickels equals $7.00 but we are not done we still need that 45 cents,so how much nickels equals 45 cents it's 9 nickels so 140(nickels)+9(nickels)=149 nickels so the answer is 149 nickels