ACS Primary 2009 PSLE Math Prelim Paper 2 Q17

65% of the animals on a farm were cows and the rest were goats. When 240 more cows and goats were added to the farm, the percentage of cows increased by 20% and the number of goats doubled. How many goats were there on the farm at first?

Solution

At first
Cows --> 65%
Goats --> 35%

Cows 20% more
--> (20/100) x 35% = 13% more

Goats doubled
--> 35% more

Total added
13% (cows) + 35% (goats) --> 240
48% --> 240
1% --> 240 divided by 48 = 5

Goats at first
35% --> 35 x 5 = 175

Answer: 175 goats

Printer Friendly Version