PSLEIan pushes two rods, Y and Z, straight into the ground until the length of each rod that is above the ground is the same.
13 of Y and
16 of Z are in the ground. The length of Y in the ground is 9 cm longer than the length of Z in the ground. What is the total length of rods Y and Z?
Fraction of Rod Y above ground
= 1 -
13 =
23 Fraction of Rod Z above ground
= 1 -
16 =
56 Heights of Rods Y and Z above ground are the same.
23 Y =
56 Z
1015 Y =
1012 Z
Length of Rod Y more than length of Rod Z
= 15 u - 12 u
= 3 u
3 u = 9
1 u = 9 ÷ 3 = 3
Total length of Rods Y and Z
= 15 u + 12 u
= 27 u
= 27 x 3
= 81 cm
Answer(s): 81 cm