PSLE A rectangular block H was cut along the dotted line into two smaller rectangular blocks of equal height, J and K, as shown. The volume of K is 25344 cm
3 more than that of J.
- What is the height of each block?
- Lee packed 6 of block K such that they fit exactly into a box with a square base. The box has the same height as K. At most, how many of block J can be packed into such a box?
(a)
Base area of Block J
= 15 x 32
= 480 cm
2 Base area of Block K
= 48 x 32
= 1536 cm
2 Base area of Block K more than Block J
= 1536 - 480
= 1056 cm
2 Height of each block
= 25344 ÷ 1056
= 24 cm
(b)
Base area of the box
= 6 x 1536
= 9216 cm
3 Length of the box
= √9216
= 96 cm
Number of Block J along the length of the box
= 96 ÷ 15
= 6 r 6
Number of Block J along the breadth of the box
= 96 ÷ 32
= 3
Number of Block J to pack into the box at most
= 6 x 3
= 18
Answer(s): (a) 24 cm; (b) 18