PSLE A rectangular block A was cut along the dotted line into two smaller rectangular blocks of equal height, B and C, as shown. The volume of C is 11520 cm
3 more than that of B.
- What is the height of each block?
- Perry packed 6 of block C such that they fit exactly into a box with a square base. The box has the same height as C. At most, how many of block B can be packed into such a box?
(a)
Base area of Block B
= 12 x 24
= 288 cm
2 Base area of Block C
= 36 x 24
= 864 cm
2 Base area of Block C more than Block B
= 864 - 288
= 576 cm
2 Height of each block
= 11520 ÷ 576
= 20 cm
(b)
Base area of the box
= 6 x 864
= 5184 cm
3 Length of the box
= √5184
= 72 cm
Number of Block B along the length of the box
= 72 ÷ 12
= 6 r 0
Number of Block B along the breadth of the box
= 72 ÷ 24
= 3
Number of Block B to pack into the box at most
= 6 x 3
= 18
Answer(s): (a) 20 cm; (b) 18