
By: shin (offline) Friday, October 22 2010 @ 08:13 AM CDT (Read 1829 times)



shin 
Hi, can someone help me on the following qtn
1) In a farm, there are some goats and ducks
There are 188 legs and 60 heads in all.
a) How many ducks are there ? Ans : 26 ducks
b) How many more goats than ducks are there ? 8 more
2) A grandfather clock chimes at a regular interval. At 3pm, it takes 6 seconds to chime 3 times.
How long it takes to chime 9 times at 9pm.
My ans is 18s but the ans is 24s

Newbie
Registered: 12/31/06 Posts: 9





By: sethchew (offline) Friday, October 22 2010 @ 09:13 PM CDT



sethchew 
actually,
you have to rely mainly on the ol'
guess and check method.
it helps.
during exams, you must at least have 3 guesses to get ur marks
for 1st qst

Junior
Registered: 10/22/10 Posts: 15





By: sethchew (offline) Saturday, October 23 2010 @ 07:50 AM CDT



sethchew 
you dont just double the time,
use a time line to help you solve this problem.
6 x 60 = 360
360/2 = 180.0
but it should be 18s.......

Junior
Registered: 10/22/10 Posts: 15





By: YFY (offline) Saturday, October 23 2010 @ 10:00 PM CDT



YFY 
Q2's answer is 24.
Chime
1st2nd3rd4th5th6th7th8th9th
+++++++++
03691215182124
Time taken (sec)
Every interval takes 3 sec. 8 intervals = 3*8 = 24

Newbie
Registered: 12/31/06 Posts: 1





By: prisneo (offline) Sunday, October 24 2010 @ 10:13 PM CDT



prisneo 
Hi see if this help.
For Qn 1, use the "if all were ...." method
Presume that if all the animals were ducks, then there should be
60 X 2 = 120 legs
188  120 = 68 extra legs
The 68 extra legs belong to the goats as each goat has 2 more legs than a duck.
68 / 2 = 34 ( the no. of goats)
60  34 = 26 (no. of ducks)
So, Qn (a) is 26 ducks

Newbie
Registered: 12/31/06 Posts: 1



