Chain Rule - General Questions (2)

Let the required weight be x kg.

Less weight, Less cost (Direct Proportion)

 250 : 200 :: 60 : x       250 x x = (200 x 60)

x=	(200 x 60)
	250

 x = 48.

Balance work =		1 -	5		=	3
			8			8

Let the required number of days be x.

Then,	5	:	3	= :: 10 : x		5	x x =	3	x 10
	8		8			8		8

x =		3	x 10 x	8
		8		5

 x = 6.

Let the required number of days be x.

Less persons, More days (Indirect Proportion)

More working hours per day, Less days (Indirect Proportion)

Persons	30	:	39		:: 12 : x
Working hours/day	6	:	5

 30 x 6 x x = 39 x 5 x 12

x =	(39 x 5 x 12)
	(30 x 6)

 x = 13.

After 10 days : 150 men had food for 35 days.

Suppose 125 men had food for x days.

Now, Less men, More days (Indirect Proportion)

 125 : 150 :: 35 : x        125 x x = 150 x 35

x =	150 x 35
	125

 x = 42.

Let the required number of bottles be x.

More machines, More bottles (Direct Proportion)

More minutes, More bottles (Direct Proportion)

Machines	6	:	10		:: 270 : x
Time (in minutes)	1	:	4

 6 x 1 x x = 10 x 4 x 270

x =	(10 x 4 x 270)
	(6)

 x = 1800.

Cost of x metres = Rs. d.

Cost of 1 metre = Rs.		d
		x

Cost of y metres = Rs.		d	. y		= Rs.		yd	.
		x					x

Let the required number of working hours per day be x.

More pumps, Less working hours per day (Indirect Proportion)

Less days, More working hours per day (Indirect Proportion)

Pumps	4	:	3		:: 8 : x
Days	1	:	2

 4 x 1 x x = 3 x 2 x 8

x =	(3 x 2 x 8)
	(4)

 x = 12.