Level 3 A basket containing 3 persimmons had a total mass of 7 kg. When 4 more persimmons were added into the basket, the total mass became 14.6 kg. Find the mass of the empty basket.
Level 3 The total mass of a kitten, a mouse and a puppy is 11 kg. The mouse is 0.4 kg heavier than the kitten. The puppy is 4 times as heavy as the mouse. Find the mass of the puppy.
Level 3 The total length of a string, a rope and a ribbon is 42.7 m. The ribbon is 14 m longer than the string. The rope is 5 times as long as the string. Find the difference in length between the rope and the ribbon.