PSLE A rectangular block V was cut along the dotted line into two smaller rectangular blocks of equal height, W and X, as shown. The volume of X is 16240 cm
3 more than that of W.
- What is the height of each block?
- Simon packed 6 of block X such that they fit exactly into a box with a square base. The box has the same height as X. At most, how many of block W can be packed into such a box?
(a)
Base area of Block W
= 13 x 28
= 364 cm
2 Base area of Block X
= 42 x 28
= 1176 cm
2 Base area of Block X more than Block W
= 1176 - 364
= 812 cm
2 Height of each block
= 16240 ÷ 812
= 20 cm
(b)
Base area of the box
= 6 x 1176
= 7056 cm
3 Length of the box
= √7056
= 84 cm
Number of Block W along the length of the box
= 84 ÷ 13
= 6 r 6
Number of Block W along the breadth of the box
= 84 ÷ 28
= 3
Number of Block W to pack into the box at most
= 6 x 3
= 18
Answer(s): (a) 20 cm; (b) 18