A girl had 20 coins in nickels and dimes whose sum was $1.40. She spent 65cents , using 8 coins. She now has ? nickels.
2 answers:
Answer:
9 Nickles
Step-by-step explanation:
Let n = number of nickles and d = number of dimes
d + n = 20 -----------(1) [ total number of coins 20 ]
Dimes = $0.10
Nickles = $0.05
0.1d + 0.05n = $1.40 ---------- (2) [20 coins worth $1.40]
Since d + n = 20
∴ n = 20 - d
Let's substitute n in equation (2)
0.1d + 0.05(20-d) = 1.40
0.1d + 1 - 0.05d = 1.40
0.1d + 0.05d = 1.40 - 1
0.05d = 0.4
d =
d = 8
Now put value of d in equation (1)
n + 8 = 20
n = 20 - 8
n = 12
Let's check 8(0.1) + 12(0.05) = $1.40
Now she spent 65 cents using 8 coins.
The only combination of 8 coins worth $0.65 is
5d + 3n = $0.65
Hence, she used 5 dimes and 3 nickles.
Now she has 12 - 3 = 9 Nickles
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Answer:
She would owe $3,700 at the end of 12 month.
Step-by-step explanation:
Simple interest formula:
= Interest
P=principal
r= Rate of interest
t=time
Given that, she could borrow $2,500. So P=$2,500.
The rate 4%=0.04 per month and time t= 12 months.
The interest = $(2,500×0.04×12)
=$1,200
Amount = principal+ Interest
=$(2,500+1,200)
=$3,700
She would owe $3,700 at the end of 12 month.