PSLE A rectangular block E was cut along the dotted line into two smaller rectangular blocks of equal height, F and G, as shown. The volume of G is 4620 cm
3 more than that of F.
- What is the height of each block?
- Vaidev packed 8 of block G such that they fit exactly into a box with a square base. The box has the same height as G. At most, how many of block F can be packed into such a box?
(a)
Base area of Block F
= 12 x 20
= 240 cm
2 Base area of Block G
= 30 x 20
= 450 cm
2 Base area of Block G more than Block F
= 450 - 240
= 210 cm
2 Height of each block
= 4620 ÷ 210
= 22 cm
(b)
Base area of the box
= 8 x 450
= 3600 cm
3 Length of the box
= √3600
= 60 cm
Number of Block F along the length of the box
= 60 ÷ 12
= 5 r 0
Number of Block F along the breadth of the box
= 60 ÷ 20
= 3
Number of Block F to pack into the box at most
= 5 x 3
= 15
Answer(s): (a) 22 cm; (b) 15