Question

the total number of students in grade 3 , 4 and 5 are 520 , if the ratio of the three grades are 4:3:6 . find the number of students in each grade​

Answer 1

Given :-

♦ The number of students in grades 3 , 4 and 5 is 520.

♦ The ratio of the number of students in the grades is 4:3:6.

To find :-

The number of students in each grade.

Solution :-

Given that

The ratio of the number of students in 3,4 and 5 grades = 4:3:6

Let they be 4X , 3X and 6X

The number of students in 3rd grade

= 4X

The number of students in 4th grade

= 3X

The number of students in 5th grade

= 6X

Total number of students in the three grades

= 4X+3X+6X

= 13X

According to the given problem

The number of students in grades 3 , 4 and 5 = 520

Therefore, 13X = 520

=> X = 520/13

=> X = 40

If X = 40 then 4X = 4(40) = 160

The number of students in 3rd grade

= 160

If X = 40 then 3X = 3(40) = 120

The number of students in 4th grade

= 120

If X = 40 then 6X = 6(40) = 240

The number of students in 5th grade

= 240

Answer :-

• The number of students in 3rd grade

= 160

• The number of students in 4th grade

= 120

• The number of students in 5th grade

= 240

Answer 2

Given

• The total number of students in grade 3,4 and 5 = 520
• Ratio of three grades = 4:3:6

To Find:-

• Number of students in each grade

Assume (as per given informations):-

• Total number of students in grade 3 = 4x
• Total number of students in grade 4 = 3x
• Total number of students in grade 5 = 6x

According to question,

$\sf \large{Ratio \: \: of \: \: three \: \: grades = 520}$

$\: \: \: \: \: \: \sf \implies \large4x + 3x + 6x = 520$

$\: \: \: \: \: \: \sf \implies13x = 520$

$\: \: \: \: \: \: \sf \implies x = \frac{520}{13} = 40$

______________________

So,

Total number of students in grade 3= 4x = 4×40 = 160 students

Total number of students in grade 4 = 3x = 3×40 = 120 students

Total number of students in grade 5= 6x = 6×40 = 240 students

_____________________

Final answer:-

$\large \sf {\boxed{ \sf{ \red{Students \: \: in \: \: grade \: \: 3 = 160 \: students}}}}$

$\large \sf {\boxed{ \sf{ \red{Students \: \: in \: \: grade \: \: 4 = 120 \: students}}}}$

$\large \sf {\boxed{ \sf{ \red{Students \: \: in \: \: grade \: \: 5 = 240\: students}}}}$