How do u solve this problem?
A bank teller has $750 in ten and twenty dollar bills. If she has twice as many twenty dollar bills as ten dollar bills, how many of each type does she have?
2007-05-01 11:03:50 · 11 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
n = number of ten dollar bills
2n = number of twenty dollar bills
10n + 20*2n = 750
50n = 750
n = 15 ten dollar bills
2n = 30 twenty dollar bills
Check:
15*10 + 30*20 = 150 + 600 = 750 Correct!
2007-05-01 11:09:35 · answer #1 · answered by ecolink 7 · 0⤊ 0⤋
I love these!
OK, let x be the number of ten dollar bills; then the number of twenties is 2x. Thus, 10* x + 20*(2x) = 750; 50x = 750, and x=15 (the number of tens); then 2x = 30 (the number of twenties).
2007-05-01 18:09:05 · answer #2 · answered by Mark S, JPAA 7 · 0⤊ 0⤋
Let x = $10 value
2(2x)+x=750
4x+x=750
5x=750
x=750/5
x=150
$150/10= 15 notes
4x=4*150= $600, $600/20= 30 notes
15*2=30, therefore there were 15 $10 notes and 30 $20 notes
2007-05-01 18:24:45 · answer #3 · answered by sexysania01 2 · 0⤊ 0⤋
Always draw a picture to start off, that's how I did it and I always got A's.
Anyway, this is how you start it off, and I won't give you an answer:
x+2x=750
and "x" represents the dollar amount of 10 dollar bills.
x is 10 dollar bills,
2x is 20 dollar bills,
add them together will give $750... now do your own work
2007-05-01 18:11:42 · answer #4 · answered by gregthedesigner 5 · 0⤊ 0⤋
750=10x+2(20x)
750=10x+40x
750=50x
15=x, so 15 $10 and 30 $20
2007-05-01 18:08:52 · answer #5 · answered by leo 6 · 0⤊ 0⤋
30 twenty dollar bills and 15 tens
2007-05-01 18:08:34 · answer #6 · answered by xxstrawberrybabygurlxx 1 · 0⤊ 1⤋
Draw a diagram.
http://en.wikipedia.org/wiki/How_to_solve_it
20(2x) + 10(x) = 750 20 stands for $20 bill, 2x twice as many. 10 stands for $10 bill, x for how many. all together they equal (=) 750.
40x+ 10x = 750
50x = 750
x=15
2x= 30
30($20) + 15($10)= $600 + $150 = $750
Please read "How to solve it " and bookmark it.
http://www.coolmath.com
2007-05-01 18:14:28 · answer #7 · answered by Anonymous · 0⤊ 0⤋
x = # of $10 bills
y = # of $20 bills
10x + 20y = 750
y = 2x
10x + 20(2x) = 750
10x + 40x = 750
50x = 750
x = 15
y = 30
2007-05-01 18:08:42 · answer #8 · answered by Mathematica 7 · 0⤊ 0⤋
x is number of $10 bills
y is number of $20 bills
10x+20y=750
y=2x
10x+40x=750
50x=750
x=15
y=30
15 $10 bills
30 $20 bills
2007-05-01 18:08:40 · answer #9 · answered by sandy 2 · 0⤊ 0⤋
20*2x +10*x=750
or 40x+10x=750
or 50x=750
so x=15
15 10's and 30 20's
2007-05-01 18:08:00 · answer #10 · answered by bruinfan 7 · 0⤊ 0⤋