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