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 294 cm
3 more than that of B.
- What is the height of each block?
- David 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
= 2 x 6
= 12 cm
2 Base area of Block C
= 9 x 6
= 54 cm
2 Base area of Block C more than Block B
= 54 - 12
= 42 cm
2 Height of each block
= 294 ÷ 42
= 7 cm
(b)
Base area of the box
= 6 x 54
= 324 cm
3 Length of the box
= √324
= 18 cm
Number of Block B along the length of the box
= 18 ÷ 2
= 9 r 0
Number of Block B along the breadth of the box
= 18 ÷ 6
= 3
Number of Block B to pack into the box at most
= 9 x 3
= 27
Answer(s): (a) 7 cm; (b) 27