Question
a purse contains 26 coins, some of which are dimes and the rest are nickels. Altogether, the coins are worth more than $2.10. At least how many dimes are in the purse?
Answers
PsyDAG
Let x = # dimes and y = # of nickels.
x + y = 26
y = 26-x
10x + 5y = 210
Substitute 26-x for y in second equation and solve for x. Insert that value into the first equation and solve for y. Check by inserting both values into the second equation.
x + y = 26
y = 26-x
10x + 5y = 210
Substitute 26-x for y in second equation and solve for x. Insert that value into the first equation and solve for y. Check by inserting both values into the second equation.
Riya
at least 17
E
at least 16