Elementary Quantitative Methods
Department of Decision Sciences
Assignment 03 for Semester 02 (compulsory)
Unique Number 701379
Due: 21 September 2020
Question 1
An investment of R5 650,00 at the simple interest rate of 8% per year, will reach R6 780,00
in (round your answer to two decimal places)
[1] 0,25 years.
[2] 15,00 years.
[3] 2,50 years.
[4] 2,37 years.
Answer:
𝑆 = 𝑃(1 + 𝑟𝑡)
𝑆
= 1 + 𝑟𝑡
𝑃
𝑆
𝑟𝑡 = (𝑃) − 1
𝑆
( )−1
𝑃
𝑡= 𝑟
6 780
( )−1 8
5 650
𝑡= (8% = 100 = 0,08)
0,08
𝑡 = 2,5
Question 2
A man took a loan from a bank at a simple interest rate of 11,5% per year. After four years
and nine months he had to pay R2 854,80 interest for the period. The principal amount
borrowed by him was
[1] R8 080,98.
[2] R5 226,18.
[3] R5 066,19.
[4] R1 702,24.