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 15360 cm
3 more than that of B.
- What is the height of each block?
- Harry packed 8 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
= 20 x 32
= 640 cm
2 Base area of Block C
= 48 x 32
= 1152 cm
2 Base area of Block C more than Block B
= 1152 - 640
= 512 cm
2 Height of each block
= 15360 ÷ 512
= 30 cm
(b)
Base area of the box
= 8 x 1152
= 9216 cm
3 Length of the box
= √9216
= 96 cm
Number of Block B along the length of the box
= 96 ÷ 20
= 4 r 16
Number of Block B along the breadth of the box
= 96 ÷ 32
= 3
Number of Block B to pack into the box at most
= 4 x 3
= 12
Answer(s): (a) 30 cm; (b) 12