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 20700 cm
3 more than that of F.
- What is the height of each block?
- Sean packed 6 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
= 15 x 30
= 450 cm
2 Base area of Block G
= 45 x 30
= 1350 cm
2 Base area of Block G more than Block F
= 1350 - 450
= 900 cm
2 Height of each block
= 20700 ÷ 900
= 23 cm
(b)
Base area of the box
= 6 x 1350
= 8100 cm
3 Length of the box
= √8100
= 90 cm
Number of Block F along the length of the box
= 90 ÷ 15
= 6 r 0
Number of Block F along the breadth of the box
= 90 ÷ 30
= 3
Number of Block F to pack into the box at most
= 6 x 3
= 18
Answer(s): (a) 23 cm; (b) 18