The sports master explained to the headmaster that 3 baseballs and 1 cricket ball

weighed the same as 14 tennis balls. He also found that 1 baseball and 6 tennis balls
exactly balanced 1 cricket ball. ‘That is interesting,’ said the headmaster, ‘and how
many tennis balls weigh the same as 1 cricket ball?’ he asked. What was the
sports master's answer?

1 answer

3b+c = 14t
b+6t = 1c

so, find c in terms of t:

c = 14t-3b = 14t-3(c-6t)
c = 14t-3c+18t
4c = 32t
c = 8t