i weigh 3kg more than my brother.our total weigh is 155.how much does my brother

Question

I weigh 3kg more than my brother.our total weight is 155kg.how much does my brother

Answer 1

your weight = your brother's weight + 3

And,    your weight + your brother's weight = 155

 

And so let's say your brother's weight equals 'x' and your weight equals 'y'.

 

So,   y = x + 3

      y + x = 155

 

So we can substitute the first equation into the second:

 

y + x = 155

(x + 3) + x = 155

2x + 3 = 155

2x = 155 - 3

2x = 152

x = 76

 

And since your brother's weight equals 'x' , then his weight is 76kg

Answer 2

If my husband is three years older than I.  How old will I be when our ages add up to one hundred fifty.