13. Nurul had $450. She spent 2/5 of it to buy a watch and 4/9 of the
remainder to buy a DVD player,
(a) How much money did she spend altogether?
(b) How much money had she left?

She spent $380 altogether and She had left $ 20

the circle graph is not a function.

step-by-step explanation:

the graph of the circle is not a function.

because for a graph to be a function, each value of x must give one value of y

in the circle, the values of x for -2< x< 2 each give 2 values of y.

hence this is not a function.