Question

What is the growth rate of sales of books at primary school level from 1975 to 1980?

• A. 29%
• B. 51%
• C. 63%
• D. 163%

Hint:

When finding growth rate, ensure you divide the increase by the initial value, not the final value. Always compare your computed value to each option to eliminate wrong answers.

Answer 1

The Correct Option is C

We are given:
Primary sales in 1975 = $42137$
Primary sales in 1980 = $68718$
Formula for growth rate:
\[ \text{Growth Rate} = \frac{\text{Final} - \text{Initial}}{\text{Initial}} \times 100 \]
Substituting:
\[ \text{Growth Rate} = \frac{68718 - 42137}{42137} \times 100 \]
\[ = \frac{26581}{42137} \times 100 \]
Now, divide:
$26581 \div 42137 \approx 0.6308$
Multiply by 100:
$0.6308 \times 100 \approx 63.08%$
Thus, the growth rate is approximately $63%$.
Checking incorrect options:
(A) 29% — much lower than the calculated value, hence incorrect.
(B) 51% — also lower than the exact 63%, so incorrect.
(D) 163% — would imply the sales more than doubled, which is far from the actual increase.
\(\boxed{\text{Correct Answer: (C) 63%}}\)