## Problem Solving

 4.6 Problem Solving

A group of students conducted a study on school history for 5 weeks and 4 days. They completed the report for their study in 1 week and 5 days. Find the duration of time they took to complete the study and the report.

SOLUTION:
Study period: 5 weeks 4 days
Report period: 1 week 5 days

Total duration: 5 weeks 4 days + 1 week 5 days = ?

\begin{aligned} 5\,\text{weeks}\;4\,\text{days}\\ \underline{+\;1\,\text{week}\;5\,\text{days}}\\ 6\,\text{weeks}\;9\,\text{days} \\\hline\end{aligned}

1 WEEK = 7 DAYS
6 weeks 9 days = 7 weeks 2 days

5 weeks 4 days + 1 week 5 days = 7 weeks 2 days

 EXAMPLE 2: SUBTRACTION

Amri is 8 years 3 months old. The difference between Amri's age and his little brother's age is 2 years 7 months. Find his little brother's age.

SOLUTION:
Amri's age: 8 years 3 months
Little brother's age: 2 years 7 months younger than Amri

Little brother's age: = 8 years 3 months - 2 years 7 months

1 YEAR = 12 MONTHS
8 years 3 months = 7 years 15 months

\begin{aligned} 7\,\text{years}\;15\,\text{months}\\ \underline{-\;2\,\text{years\,\,}\;7\,\text{months}}\\ 5\,\text{years\,\,}\;8\,\text{months} \\\hline\end{aligned}

8 years 3 months - 2 years 7 months = 5 years 8 months
Little brother's age: 5 years 8 months

 EXAMPLE 3: MULTIPLICATION

The lifespan of a jungle cat is around 5 years. The lifespan of a tiger is 3 times longer than a jungle cat. Calculate the lifespan of a tiger in months.

SOLUTION:
Lifespan of a jungle cat: 5 years
Lifespan of a tiger: 3 x 5 years = 15 years

Lifespan of a tiger in months:
15 x 12 = 180 months

 EXAMPLE 4: DIVISION

Bryan finished reading a thick novel in 3 weeks 1 day. Azizah finished the same novel but only took half of the time Bryan needed. Find the time needed for Azizah to finish the novel, in days.

SOLUTION:
1 WEEK = 7 DAYS

Time needed by Bryan: 3 weeks 1 day → 22 days
Time needed by Azizah: 22 days ÷ 2 = 11 days