Krishaun has $5, $10, and $20 coins worth a total of $560. She has the same number of $5 coins as $10 coins, and the same number of $10 coins as $20 coins. How many $20 coins does Krishaun have?a.16
b.15
c.20
d.28
e.17
+37159 f = t = n five ten and twenty
5n + 10n + 20n = 560
35n = 560
n = twenty dollar coins = 16
+240 Let's make the number of 5 coins 'a', number of 10 coins 'b', and the number of 20 coins 'c'. Writing as an equation we get,
\(5a+10b+20c=560\)
\(a+2b+4c=112\)
We also know that she has the same amount of all coins, so we can replace a, b, c, with a common variable of 'x'.
\(x+2x+4x=112\)
\(x = 16\)
Because x is equal to the amount of each of the coins, she has 16 $20 coins.
