Sarah says that -6 multiplied by -3 is -18. Joseph says -6 multiplied by -3 is 18. Who is correct? Explain.

Find the balance at the end of 4 years if 1000 is deposited at the rate of

Some boys and girls were asked if they had a pet. one third of the group were boys. there were 20 boys. 20% of the girls had a pet. boys with a pet : girls with a pet = 1 : 5 i need to know how many girls there are.

How is this equation completed? i cannot find any examples in the book.