Answer:
See below, please.
Step-by-step explanation:
1. (a) 9/24 = 0.375 = 37.5% (multiply by 100 and put a % sign on the end)
(b) 60% = 'x' karats
0.60 = x/24
x = (0.60)(24) = 14.4 karats
2. (a) 2g 10-karat gold + 2g 14-karat gold
= (2g * 10/24) + (2g * 14/24) = (20/24 + 28/24)g = (48/24)g = 2g Gold in a 4-gram alloy, so it is 50% gold
(b) 6g 24-karat gold + 4g 9-karat gold
= (6g * 24/24) + (4g * 9/24) = (144/24 + 36/24)g = (180/24)g = 7.5g Gold in a 10-gram alloy, so it is 75% gold
