Asked by bobby

Dudley has a number of 10c and 20c coins. If their total is $6, how many are there of each coin if there are:
a) equal numbers of each coin?
b) twice as many 10c coins as 20c coins
Answered by oobleck
(a) 10x + 20x = 600
(b) 10*2x + 20x = 600
in each case, solve for x and in (b) find 2x