Carlo has 35 stamps. Some are valued at 2 cents, others at 5 cents and the remainder at 10 cents. He has 3 times as many 5 cent stamps as he has 2 cent stamps and the total value of all stamps is $1.89. How many of each stamp does he have?

Question

anonymous · Answer

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anonymous · Answer

He will have 7 2 cent stamps, 21 5 cent stamps and 7  10 cent stamps

anonymous · Answer

if $x$ is the number of 2cent stamps, he has $3x$ 5 cent stamps and $35-4x$. Then you say the cost of these stamps is $(2 * x)+5 * (3x) + 10 * (35-4x) = 189$ solving for x you get $2x+15x+350-40x = 189$. collecting terms you get $-23x = -161$. and so x is -161/-23 = 7. substitute that back into the equations for the numbers of each stamps to get how many there are of each type

anonymous · Answer

in the first line, i meant to say there are 35 - 4x 10 cent stamps