Cognizant Inverse Quiz-1

Assume that in x days, one cow will eat one bag of husk.

More cows, less days (Indirect proportion)
More bags, more days (direct proportion)

Hence we can write as

Let the required number days be x.

Less spiders, More days (Indirect Proportion)

Less webs, Less days (Direct Proportion)

Spiders 1:7

Webs 7:1

⋮⋮ 7:x

 

=> 1 * 7 * x = 7 * 1 * 7

=> x= 7

Given that fort had provision for 500 persons for 27 days
Hence, after 3 days, the remaining food is sufficient for 500 persons for 24 days

Remaining persons after 3 days = 500 + 300 = 800
Assume that after 10 days,the remaining food is sufficient for 800 persons for x days

More men, Less days (Indirect Proportion)
⇒Men500:800}::x:24
⇒500×24=800x⇒5×24=8x⇒x=5×3=15

 

ALTERNATE EXPLANATION

We can use the concept of ManDays here as well

M1*D1=M2*D2

500*24=300*D2

D2= 15 days

Because, less number of basket balls -----> cost will be less
Given : 75 basketballs cost $1,143.75
Cost of one basket ball = 1143.75 / 75 = 15.25
Then, cost of 26 basket balls = 15.25 x 26 = 396.50
Hence, the cost of 26 basket balls is $ 396.50

Miguel raised $2,372.50 in 36.5 weeks

Amount raised in one week is

=  2372.5 / 36.5

=  $65

Amount raised in 20 weeks is

=  65 ⋅ 20

=  $1300

Hence, the money raised in 20 weeks is $1300

Let x be the required length of the wall.

More men means more work will be done. (Therefore, Amount of work is directly proportional to Number of men)

Less days means less length built. (Therefore, number of days of work is directly proportional to length of wall built)

Men: 30 40 : 56 meters

Days: 5 3 : x meters

Therefore, we have:

30/50 x 5/3 =56/ x

30 x5x X=56 x40 x 3

150 x X=6720

x={6720}/{150}

x=44.8

20 cows : 20 bags : 20 days = 1 cow : 1 bag : x days
20 : 20 : 20 = 1 : 1 : x
20 / 20 : 20 = 1 / 1 : x
1 : 20 = 1 : x
1 / 20 = 1 / x
x = 20
which shows that 1 cows will eat 1 bag of husk in 20 days.

 

4 men in 30 days reap 40acres
1man in one day will reap 40/(4*30)=1/3acre
18men in 12days will reap 1/3*18*12=72 acres

Answer sheets are work here. So
M1*D1*H1*W2 = M2*D2*H2*W1
9*12*5*2 = 4*30*H2*1
Solve, H2 = 9