The confetti will fit in the jar only if the volume of the jar is greater than or equal to the volume of the confetti that is in the bag.
Volume of confetti = 100 cubic inches
Since the jar is shaped like a square prism, its volume will be the product of its base area and the height.
So,
Volume of Square Prism = Base Area x Height
Volume of Square Prism = (3 x 3) x 10 cubic inches
Volume of Square Prism = 9 x 10 cubic inches = 90 cubic inches
Since volume of the jar is less than the volume of confetti, all the confetti will NOT FIT in the given jar.