Question

a+b=280,30%din a=40%din b, a, b=?

Answer 1

30/100*a = 40/100*b => 3/10*a = 2/5*b => 3a=2/5b * 10 => 3a = 4b => a = 4b/3
a+b=280 => 4b/3 + b = 280 => 4b + 3b = 840 => 7b = 840 => b = 840/7 = 120
a = 4*120/3 = 160