44 baskets of strawberries are sold
Solution:
Let "a" be the number of baskets of strawberries sold
Let "b" be the number of raspberries sold
Cost of 1 basket of strawberries = $ 4
Cost of 1 basket of raspberries = $ 9
96 baskets were sold. Therefore, we can say,
number of baskets of strawberries + number of raspberries sold = 96
a + b = 96
b = 96 - a ------------- eqn 1
In one morning, Katya sells 96 baskets for $644
Thus we frame a equation as:
4a + 9b = 644 ----------- eqn 2
Let us solve eqn 1 and eqn 2
Substitute eqn 1 in eqn 2
4a + 9(96 - a) = 644
4a + 864 - 9a = 644
5a = 864 - 644
5a = 220
Divide both sides by 5
a = 44
Thus 44 baskets of strawberries are sold