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 19140 cm
3 more than that of B.
- What is the height of each block?
- Wesley 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
= 16 x 30
= 480 cm
2 Base area of Block C
= 45 x 30
= 1350 cm
2 Base area of Block C more than Block B
= 1350 - 480
= 870 cm
2 Height of each block
= 19140 ÷ 870
= 22 cm
(b)
Base area of the box
= 6 x 1350
= 8100 cm
3 Length of the box
= √8100
= 90 cm
Number of Block B along the length of the box
= 90 ÷ 16
= 5 r 10
Number of Block B along the breadth of the box
= 90 ÷ 30
= 3
Number of Block B to pack into the box at most
= 5 x 3
= 15
Answer(s): (a) 22 cm; (b) 15