The lost pair of weight can be found by subtracting the a known pair from
the total weight leaving the value of the lost pair.
<u>The lost weight of a pair of boys is 120 kg</u>
Reasons:
Let <em>a</em>, <em>b</em>, <em>c</em>, and <em>d</em><em> </em>represent the weights of the four boys, we have;
The number of ways of selecting pairs (two boys) of boys from a group of
four is given using combination formula as follows;
Which gives;
₄C₂ = 6
Therefore, the weights of the pairs are;
a + b = 110
a + c = 112
a + d = 113
b + c = 118
b + d = 121
c + d = Lost weight
- c + d = Lost weight
a + b + c + d = 230 (given)
Therefore;
The lost weight, c + d = 230 - (a + b)
Which gives;
c + d = 230 - (110) = 120
The lost weight = c + d = 120
- <u>The lost weight = 120 kg</u>
Learn more here: