Pei Chun Public Sch 2007 PSLE Math Prelim Q45

400 people took part in a camp. 73 of them were adults and the rest were children. 2/5 of the boys and ¼ of the girls were lower primary pupils while the rest of them were upper primary pupils. There were 9 more upper primary girls than upper primary boys.
a) How many upper primary pupils were there?
b) What percentage of the people who took part in the camp were girls?

Solution

400 people – 73 adults ----- 327 children



12 parts + 15 parts ----- 981 + 45
27 parts ----- 1026
1 part ----- 1026 divided by 27 = 38

a)
(Upp Pri Girls) 3 parts ---- 3 x 38 = 114
(Upp Pri Boys) 114 – 9 = 105
Total Upper Pri ----- 114 + 105 = 219
Answer: There were 219 upper primary pupils.

b)
(Total Girls) 4 parts ----- 38 x 4 = 152
Percentage of girls ----- (152/400) x 100% = 38%
Answer: 38% were girls.