Maths(Formulas)

Time And Distance (Related Formulas)

1. Speed =

Distance

,

Time =

Distance

,

Distance = (Speed x Time).

2. km/hr to m/sec conversion:  x km/hr = x x 5 m/sec.

3.m/sec to km/hr conversion:

x m/sec =

x x

18

km/hr.

4.If the ratio of the speeds of A and B is a : b, then the ratio of the times taken by then to cover the same distance is

1 : 1 or b : a.                             a b

5.Suppose a man covers a certain distance at x km/hr and an equal distance at y km/hr. Then,the average speed during the whole journey is
                      

	2xy		km/hr.
	x + y

Selling And Cost Price (Related Formulas)

Cost Price:
The price, at which an article is purchased, is called its cost price, abbreviated as C.P.
Selling Price:
The price, at which an article is sold, is called its selling prices, abbreviated as S.P.
Profit or Gain:
If S.P. is greater than C.P., the seller is said to have a profit or gain.
Loss:
If S.P. is less than C.P., the seller is said to have incurred a loss.

      IMPORTANT FORMULAE

1. Gain = (S.P.) - (C.P.)
   
2. Loss = (C.P.) - (S.P.)
   
3. Loss or gain is always reckoned on C.P.
   
4. Gain Percentage: (Gain %)

Gain % =		Gain x 100
		C.P.

Loss Percentage: (Loss %)

Loss % =		Loss x 100
		C.P.

Selling Price: (S.P.)

SP =		(100 + Gain %)	x C.P
		100

Selling Price: (S.P.)

SP =		(100 - Loss %)	x C.P.
		100

Cost Price: (C.P.)

C.P. =		100	x S.P.
		(100 + Gain %)

Cost Price: (C.P.)

C.P. =		100	x S.P.
		(100 - Loss %)

If an article is sold at a gain of say 35%, then S.P. = 135% of C.P.

If an article is sold at a loss of say, 35% then S.P. = 65% of C.P.

When a person sells two similar items, one at a gain of say x%, and the other at a loss of x%, then the seller always incurs a loss given by:

Loss % =		Common Loss and Gain %		2	=		x		2	.
		10					10

If a trader professes to sell his goods at cost price, but uses false weights, then

Gain % =		Error	x 100	%.
		(True Value) - (Error)

  Time And Work(Related Formulas)

1. Work from Days:
   

   If A can do a piece of work in n days, then A's 1 day's work =	1	.
   	n

2. Days from Work:
   

   If A's 1 day's work =	1	,	then A can finish the work in n days.
   	n

3. Ratio:
   If A is thrice as good a workman as B, then:
   Ratio of work done by A and B = 3 : 1.
   Ratio of times taken by A and B to finish a work = 1 : 3.