m = −3/4 is the correct answer. Hope this helps!
Answer:
b=9,a=12
Step-by-step explanation:
I solved by substitution:
b = 3/4a ---> plug this into the other equation
a + b = 21 is now a + 3/4a = 21
Reduce: 7/4a = 21
a = 12
Now solve for b:
b=3/4a is now b=3/4(12)
b=9
Given:
Principal = Rs. 2000
Rate of interest = 20% p.a. compounded quarterly.
Time = 1 year
To find:
The compound interest.
Solution:
Formula for amount:
![A=P\left (1+\dfrac{r}{n}\right)^{nt}](https://tex.z-dn.net/?f=A%3DP%5Cleft%20%281%2B%5Cdfrac%7Br%7D%7Bn%7D%5Cright%29%5E%7Bnt%7D)
where,
P = Principal
r = Rate of interest
t= Time
n = number of times interest compounded in an year.
Putting P=2000, r=0.2, n=4 and t=1, we get
![A=2000\left (1+\dfrac{0.2}{4}\right)^{4(1)}](https://tex.z-dn.net/?f=A%3D2000%5Cleft%20%281%2B%5Cdfrac%7B0.2%7D%7B4%7D%5Cright%29%5E%7B4%281%29%7D)
![A=2000\left (1.05\right)^{4}](https://tex.z-dn.net/?f=A%3D2000%5Cleft%20%281.05%5Cright%29%5E%7B4%7D)
![A=2000\left (1.21550625\right)](https://tex.z-dn.net/?f=A%3D2000%5Cleft%20%281.21550625%5Cright%29)
![A=2431.0125](https://tex.z-dn.net/?f=A%3D2431.0125)
Now, the compound interest is
![C.I.=A-P](https://tex.z-dn.net/?f=C.I.%3DA-P)
![C.I.=2431.0125-2000](https://tex.z-dn.net/?f=C.I.%3D2431.0125-2000)
![C.I.=431.0125](https://tex.z-dn.net/?f=C.I.%3D431.0125)
Therefore, the compound interest is Rs 431.0125.
Answer:
D
Step-by-step explanation:
6cm