Answer:
He can buy 12 notebooks Type A and 9 notebooks Type B.
Explanation:
Type A = $1.50
Type B = $3.00
Spending money = $45
Note: He must have at least 6 of each item. 
Type A 
He can buy 12 notebooks 
12 x $1.50 = $18 
Type B
He can buy 9 notebooks 
9 x $3.00 = $27