Question 1194331
A treasure chest contains 70 gold coins, 50 silver coins, and 100 bronze coins.
 How many additional gold coins must be added to the 220 coins already in the treasure chest so that half of the coins in the treasure chest are gold? 
:
let g = no. of gold coins that have to be added
g + 70 = .5(g + 220)
g + 70 = .5g + 110
g - .5g = 110 - 70
.5g = 40
g = 80 gold coins to be added
:
Check:
 80 + 220 = 300
 70 + 80 = 150, half of the total