Respuesta :

Answer:

15 boys

Step-by-step explanation:

7+3=10

10x5=50

there are 3 boys so

3x5=15

Answer:

35

Step-by-step explanation:

Assume 3x is the number of boys in the class.

And 7x as for the girls.

3x+7x=50

10x=50

x=5

Thus, 7*5=35 boys in the science class

Hope this is helpful!