# Sarin participates in school anniversary event part 31 (Math Question)

Standard

The blog postings are about the Singapore Math. The readers can learn from the postings about Solving Singapore Primary School Mathematics. The blog presents the Math Concept, the Math Questions with solutions that teaches in Singapore Primary Schools. You or the kids can learn the skills to deal with the Math Modeling, the Math Problem Solving and the Problem Sum from Lower Primary School to Upper Primary School level after reading the blog postings. This posting is an upper primary school math question on Percentage, Ratio, Fraction and Problem Solving.

Sarin learns concept of Fraction (Mathematics concept)

Sarin learns Average Number, Percentage and Charting in school (Math Concept)

Sarin learns concept of ratio in school

Challenge yourself with the question before look out for the given solution!!!

Upper primary school mathematics question UPQ587

There were 352 people attended the anniversary dinner in the school hall. 75% of them were invited guests and the rest were students. Later in the night, some invited guests decided to leave and the number of invited guests was 3/5 that of the total number of people in the hall.

How many invited guests decided to leave the dinner?

Solution:

The number of invited guests at first = 352 × 75% = 264

The number of students at first = 352 – 264 = 88

No student had left the hall,

Hence,

At final, 2/5 of the people in the hall were students,

2 units = 88

1 unit = 44

The number of invited guests finally = 3 × 44 = 132

The number of invited guests left the club = 264 – 132 = 132

Alternative solution(1): Per the model,

8 units = 352

1 unit = 44

The number of guests left the dinner

= 3 × 44

= 132

Alternative solution(2):

75% people in the dinner were invited guests,

Guests : Students : Total = 75 : 25 : 100 = 3 : 1 : 4 = 6 : 2 : 8

Finally,

Guests : Students : Final Total = 3 : 2 : 5

There were no students left the hall,

8 units = 352

1 unit = 44

Guests left the dinner in unit = 6 – 3 = 3 units

The number of guests left the dinner

= 3 × 44

= 132