Question

Bell metal which is a form of bronze is used for casting bells. It is an alloy of copper and tin. To make bell metal requires 17 parts of copper to every 3 parts of tin. (6) (i) Express this requirement as a ratio (ii) Express the amount of tin required as a percentage of the total (iii) If the total amount of tin in a particular casting is 150 kg, find the amount of copper

Answer 1

you need 17 parts copper and 3 parts tin in order to make brass

1. ratio of copper with respect to brass: 17:20

ratio of tin with respect to brass: 3:20

ratio of tin with respect to copper: 3:17

2. percentage of tin required in brass: fraction of tin in brass X 100

3/20 X 100 = 15%

3. if we used 150 kg tin in the alloy, then 150 kg is 15 % of the alloy

(from last answer)

150/x X 100 = 15%

x = 1000 kg

if the total brass formed is 1000 kg, and 150 kg of it is tin,

copper used = 1000 - 150 = 850 kg copper