PSLE A rectangular block F was cut along the dotted line into two smaller rectangular blocks of equal height, G and H, as shown. The volume of H is 7200 cm
3 more than that of G.
- What is the height of each block?
- Owen packed 6 of block H such that they fit exactly into a box with a square base. The box has the same height as H. At most, how many of block G can be packed into such a box?
(a)
Base area of Block G
= 12 x 20
= 240 cm
2 Base area of Block H
= 30 x 20
= 600 cm
2 Base area of Block H more than Block G
= 600 - 240
= 360 cm
2 Height of each block
= 7200 ÷ 360
= 20 cm
(b)
Base area of the box
= 6 x 600
= 3600 cm
3 Length of the box
= √3600
= 60 cm
Number of Block G along the length of the box
= 60 ÷ 12
= 5 r 0
Number of Block G along the breadth of the box
= 60 ÷ 20
= 3
Number of Block G to pack into the box at most
= 5 x 3
= 15
Answer(s): (a) 20 cm; (b) 15