Always ensure that the operands in concatenation operations are of the same data type. Use str() to convert integers to strings if needed.
print("A"*3)
print(5*3)
print("15" + 3)
print("15" + "13")
"A"*3 repeats the string "A" three times, resulting in "AAA".5*3 performs integer multiplication, resulting in 15."15" + "13" concatenates two strings, resulting in "1513"."15" + 3 raises a TypeError because Python does not allow concatenation of a string ("15") and an integer (3).If vector \( \mathbf{a} = 3 \hat{i} + 2 \hat{j} - \hat{k} \) \text{ and } \( \mathbf{b} = \hat{i} - \hat{j} + \hat{k} \), then which of the following is correct?