Simple and Compound Interest Formula
Simple and Compound Interest FormulaP - Principal, the sum of money lent or borrowed.
R - Rate of interest: Annual interest, often expressed as a percentage.
T - Time period for which the money is lent or borrowed.
Simple Interest = Principal * Time * Rate of interest / 100
SI = P * T * R
For example, Principal is 4000, Rate of Interest is 8% and Time period is 4 years
SI = 4000× 8% × 4 = 4000× 0.08 × 4
= 1280.
In compound interest, the principal amount with interest after the first time period becomes the part of principal for the next time period.
CI = [P (1 + R/100)^T] – P
Total amount = [P (1 + R/100)^T]
If time period is half-yearly,
Amount = P[1 + (R/2)/100]^2T
If time period is quarterly,
Amount = P[1 + (R/4)/100]^4T
For example, Principal is 7500, Rate of Interest is 4% (compounded annually) and Time period is 2 years
Total Amount = [7500×(1+4/100)^2] = 8112.
CI = (8112 - 7500) = 612.
Formula : .
Train Speed = Distance / Time.
Points to Remember .
To change km/hr into m/sec, we need to multiply it by 5 / 18. .
Example:.
90 km/hr means.
90 x 5 / 18.
= (5 x 5 ).
= 25 m/sec.
And if we need to convert m/sec into km/hr, we multiply it by 18 / 5.
Example:.
90 m/sec means.
90 x 18 / 5.
= ( 18 x 18 ).
= 324 km/hr.
Time taken by a train of length l meters to pass a pole or standing man or a signal post is equal to the time taken by the train to cover l meters.
Time taken by a train of length l meters to pass a stationary object of length b meters is the time taken by the train to cover (l + b) meters.
Suppose two trains or two objects bodies are mo...
Problems Type 1: .
A can finish work in X days. .
B can finish work in Y days.
Both can finish in Z days = (X*Y) / (X+Y). .
Problems Type 2: .
Both A and B together can do work in T days.
A can do this work in X days.
then, B can do it in Y days = (X*T) / (X-T) .
Problems Type 3: .
A can finish work in X days.
B can finish work in Y days.
C can finish work in Z days.
Together they can do work in T days = (X*Y*Z)/ [(X*Y)+(Y*Z)+(X*Z)] .
Problems Type 4: .
A can finish work in X days.
B can finish work in Y days.
A*X = B*Y.
...
Important Maths Formulas .
(a ± b) 2 = a 2 ± 2ab + b 2 .
(a + b + c) 2 = a 2 + b 2 + c 2 + 2(ab + bc + ca).
(a + b + c + d) 2 = a 2 + b 2 + c 2 + d 2 + 2(ab + ac + ad + bc + bd + cd) .
Geometry formulas .
Perimeter ( ചുറ്റളവ് ) .
Perimeter of a square: P=4a.
a: length of one side.
Perimeter of a rectangle: P=2(l+w).
l: length.
w: width.
Perimeter of a triangle: P=a+b+c.
a, b, and c: lengths of the 3 sides.
Area ( വിസ്തീര്ണ്ണം ) .
LINE_FE...
















