Answer:
volume of toy = volume of water after placing toy in it - volume of water before placing toy in it
volume of toy = 23mL - 10mL
volume of toy = 13mL
The increase in the volume of water when the toy is submerged in it is equal to the volume of the toy.
SO VOLUME OF WATER IS 13mL
2a) 30
2 x 15
3 x 5
30=2x3x5
2b) 60
6 x 10
2x3 2x5
60=2x3x2x5
Hi! You need 3 boxes because if you divide 21 1/4 / 10 you get 2 1/8 or 2.125 so you at least have two boxes. You will still have some left over after the two boxes so you will need another box for those. I hope this helped, Goodluck :)