PSLE A rectangular block W was cut along the dotted line into two smaller rectangular blocks of equal height, X and Y, as shown. The volume of Y is 5808 cm
3 more than that of X.
- What is the height of each block?
- Lee packed 8 of block Y such that they fit exactly into a box with a square base. The box has the same height as Y. At most, how many of block X can be packed into such a box?
(a)
Base area of Block X
= 16 x 24
= 384 cm
2 Base area of Block Y
= 36 x 24
= 648 cm
2 Base area of Block Y more than Block X
= 648 - 384
= 264 cm
2 Height of each block
= 5808 ÷ 264
= 22 cm
(b)
Base area of the box
= 8 x 648
= 5184 cm
3 Length of the box
= √5184
= 72 cm
Number of Block X along the length of the box
= 72 ÷ 16
= 4 r 8
Number of Block X along the breadth of the box
= 72 ÷ 24
= 3
Number of Block X to pack into the box at most
= 4 x 3
= 12
Answer(s): (a) 22 cm; (b) 12