Answer :
To determine the value of the book on the 1st May 2018, given its value on the 1st May 2019 was £15 and it increased by 20% over the year, follow these steps:
1. Let's denote the value of the book on the 1st May 2018 as [tex]\( V_{2018} \)[/tex].
2. We know that the value of the book increased by 20%. This means that the value of the book on the 1st May 2019, which is £15, is 120% of its value on the 1st May 2018.
3. To express this relationship mathematically:
[tex]\[ V_{2019} = V_{2018} \times 1.20 \][/tex]
Given that [tex]\( V_{2019} \)[/tex] is £15:
[tex]\[ 15 = V_{2018} \times 1.20 \][/tex]
4. To find [tex]\( V_{2018} \)[/tex], we need to isolate it by dividing both sides of the equation by 1.20:
[tex]\[ V_{2018} = \frac{15}{1.20} \][/tex]
5. Performing the division:
[tex]\[ V_{2018} = \frac{15}{1.20} = 12.5 \][/tex]
Thus, the value of the book on the 1st May 2018 was £12.5 (or £12.50).
1. Let's denote the value of the book on the 1st May 2018 as [tex]\( V_{2018} \)[/tex].
2. We know that the value of the book increased by 20%. This means that the value of the book on the 1st May 2019, which is £15, is 120% of its value on the 1st May 2018.
3. To express this relationship mathematically:
[tex]\[ V_{2019} = V_{2018} \times 1.20 \][/tex]
Given that [tex]\( V_{2019} \)[/tex] is £15:
[tex]\[ 15 = V_{2018} \times 1.20 \][/tex]
4. To find [tex]\( V_{2018} \)[/tex], we need to isolate it by dividing both sides of the equation by 1.20:
[tex]\[ V_{2018} = \frac{15}{1.20} \][/tex]
5. Performing the division:
[tex]\[ V_{2018} = \frac{15}{1.20} = 12.5 \][/tex]
Thus, the value of the book on the 1st May 2018 was £12.5 (or £12.50).
Answer:
12.5
Step-by-step explanation:
To find the value of the book on the 1st of May, 2018 we can make a formula:
[tex]l \times 1.2 = n[/tex]
Where:
- l means last year's value
- n means next year's value = 15
- 1.2 is represented by adding 20% (0.2) to the last year's value
Making l the subject of formula:
[tex]l \times 1.2 = n\\\\l = \frac{n}{1.2}[/tex]
l = 15/1.2
l = 12.5
Therefore, the value of the book last year (1st May, 2018) simplifies to:
[tex]\boxed{\boxed{12.5}}[/tex]
