Sunday

April 19, 2015

April 19, 2015

Posted by **m** on Wednesday, April 9, 2014 at 2:15am.

- math -
**Reiny**, Wednesday, April 9, 2014 at 6:54amnumber of dimes ---- x

number of quarters --- 21-x

by value:

10x + 25(21-x) = 405

10x + 525 - 25x = 405

-15x = -120

x = 8

so 8 dimes and 21-8 or 13 quarters

or

dimes ---- d

quarters ---q

based on numbers:

d+q = 21

based on value:

10d + 25q = 405 --- 2d + 5q = 81

double the first:

2d + 2q = 42

subtract from the 2nd to give

3q = 39

q = 13

back into the first:

d + q = 13

d = 8

I find the first method easier.

math - There are 60 coins in a box containing only nickels, dimes, and quarters...

math - can someone help explain how to do this? allen has nickels dimes and ...

word problem money - you have $ 1.55 in dimes and quarters. find all the ...

Math- urgent - Solving Systems by Substitution Maribel has $1.25 in her pocket. ...

math - Sal keeps quarters, nicles, and dimes in his change jar. He has a total ...

Math - Ruthie has 10 coins, all either nickels, dimes, or quarters. She has N ...

Algebra 1 - Janella has only quarters dimes and pennies in her pocket thee are ...

Maths algebra 1 - Janella has only quarters dimes and pennies in her pocket ...

Algebra - Alycia's pggy bank has dimes and quarters in it. The numbers of dimes ...

math - Sal keeps quarters, nickels, and dimes in his change jar. He has a total ...