Answer:

400

Step-by-step explanation:

Given

Total number of girls = 100

Number of boys = 4 / 5

Let us assume the total number of boys and girls be x

Total number of boys = 4 / 5 of x

We get,

= 4x / 5

According to question, total strength of school can be calculate as below

Number of boys = Total strength – Girls

= 500 – 400

= 400

Hence number of boys are 400

Step-by-step explanation:

Total number of girls = 100

Number of boys = 4/5

Let us assume the total number of boys and girls be x

Total number of boys = 4 / 5 of x

We get,

= 4x / 5

According to question, total strength of school

=> x-4x/5 = 100

=> 5x-4x/5= 100

=> X/5= 100

=> X = 500

Number of boys = Total strength(X) – Girls

=500 – 100

= 400

Hence number of boys are 400

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