PSLE A rectangular block T was cut along the dotted line into two smaller rectangular blocks of equal height, U and V, as shown. The volume of V is 4000 cm
3 more than that of U.
- What is the height of each block?
- Henry packed 8 of block V such that they fit exactly into a box with a square base. The box has the same height as V. At most, how many of block U can be packed into such a box?
(a)
Base area of Block U
= 10 x 20
= 200 cm
2 Base area of Block V
= 30 x 20
= 450 cm
2 Base area of Block V more than Block U
= 450 - 200
= 250 cm
2 Height of each block
= 4000 ÷ 250
= 16 cm
(b)
Base area of the box
= 8 x 450
= 3600 cm
3 Length of the box
= √3600
= 60 cm
Number of Block U along the length of the box
= 60 ÷ 10
= 6 r 0
Number of Block U along the breadth of the box
= 60 ÷ 20
= 3
Number of Block U to pack into the box at most
= 6 x 3
= 18
Answer(s): (a) 16 cm; (b) 18