A student has 5 subjects in an examination. The distribution of hard work of 16 hours a day over 5 subjects and marks obtained 400 out of 500 are shown in the charts.

How much time did the student spend on Math and how much marks were obtained in math?

The correct option is 6.4 hrs and 84 marks.

From the given pie charts in the image:

1. Calculating the time spent on Math:

Total time spent per day = 16 hours

Percentage of time spent on Math (from the "Hardwork in time" pie chart) = 40%

$\text{Time spent on Math}=40\%\×16\text{\ hours}$

$\text{Time spent on Math}=\frac{40}{100}\×16=0.4\×16=6.4\text{\ hours}$

2. Calculating the marks obtained in Math:

Total marks obtained out of 500 = 400 marks

Percentage of marks obtained in Math (from the "Marks obtained" pie chart) = 21%

$\text{Marks obtained in Math}=21\%\×400$

$\text{Marks obtained in Math}=\frac{21}{100}\×400=21\×4=84\text{\ marks}$

Thus, the student spent 6.4 hrs on Math and obtained 84 marks in Math.