Question

The amount of Beta rays in 10 minutes of the sun's rays is how many times the amount of IR rays in 3 minutes of the sun's rays?

• A. 1.44
• B. 1.33
• C. 1.66
• D. 1.55

Hint:

Always simplify ratios by canceling a common factor; it reduces arithmetic and reveals exact fractions (e.g., \(1800/1080 = 5/3\)).

Answer 1

The Correct Option is C

Step 1: Per-minute quantities from the pie chart. 
Beta rays share \(= 5\%\) \(\Rightarrow\) Beta/min \(= \dfrac{5}{100}\times 3600 = 180\) units/min. 
IR rays share \(= 10\%\) \(\Rightarrow\) IR/min \(= \dfrac{10}{100}\times 3600 = 360\) units/min. 

Step 2: Compute required amounts for the given times. 
Beta in \(10\) minutes \(= 180 \times 10 = 1800\) units. 
IR in \(3\) minutes \(= 360 \times 3 = 1080\) units. 

Step 3: Form the ratio (times as many). 
\(\dfrac{\text{Beta in 10 min}}{\text{IR in 3 min}} = \dfrac{1800}{1080}\). 
Reduce: divide numerator and denominator by \(60\) \(\Rightarrow \dfrac{30}{18} = \dfrac{5}{3} = 1.\overline{6}\). 
So ratio \(= 1.666\ldots \approx \boxed{1.66}\).