In a class there are 5 more boys than girls. There are 13 students in all. How many boys are there i

Discussion in 'Calculator Requests' started by math_celebrity, Oct 20, 2021.

  1. math_celebrity

    math_celebrity Administrator Staff Member

    In a class there are 5 more boys than girls. There are 13 students in all. How many boys are there in the class?

    We start by declaring variables for boys and girls:
    • Let b be the number of boys
    • Let g be the number of girls
    We're given two equations:
    1. b = g + 5
    2. b + g = 13
    Substitute equation (1) for b into equation (2):
    g + 5 + g = 13

    Grouping like terms, we get:
    2g + 5 = 13

    Subtract 5 from each side:
    2g + 5 - 5 = 13 - 5

    Cancel the 5's on the left side and we get:
    2g = 8

    Divide each side of the equation by 2 to isolate g:
    2g/2 = 8/2

    Cancel the 2's on the left side and we get:
    g = 4

    Substitute g = 4 into equation (1) to solve for b:
    b = 4 + 5
    b = 9
     

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