The total cost of 12 pens and 5 pencils is equal to ? 111. Also, the cost of 1 pencil is ? 5 less than the cost of 1 pen. What will be the cost of 8 pens and 9 pencils?

Adult fare = ? 114
According to the question,
child fare = Adult fare x 1/6
= 144 x 1/6 = ? 19
? Total amount paid by 4 adults and 5 children are for the same distance.
= ?(4 x 144 + 5 x 19)
= ?(456 + 95) = ? 551

Let at present, there are c men, then number of women = 5c
Before the men had left
number of men = c + 45 and
number of women = 5c
? c + 45 = 2 x 5c
? 9c = 45
? c = 45/9 = 5
Hence, number of women in the beginning
= 5c + 15 = 5 x 5 + 15
= 25 + 15 = 40
? Double of the women = 40 x 2 = 80

Let share of each friend = a.
Then, share of each daughter = 4a.
and share of each son = 5a.
According to the question,
5 x 5a + 4 x 4a + 2 x a = 17200
? 25x + 16x + 2x = 17200
? 43x = 17200
? x = 17200/43 = 400
? Share of each daughter
= 4x = 4 x 400
= ? 1600

Hint 1.
Let consider the monthly income = x ;
Amount spend on House rent = 2x/5;
Amount spend on food = 3x/10;
Amount spend on conveyance = x/8;
After Expenditure , The left amount = 2800;

According to Question;
x - ( 2x/5 + 3x/10 + x/8 ) = 2800 ;
x- ((16x + 12x + 5x)/40) = 2800 ;
x - 33x/40 = 2800 ;
(40x - 33x)40 = 2800 ;
7x/40 = 2800 ;
7x = 2800 x 40 ;
x = 2800 x 40/7 ;
x = 400 x 40 ;
x = 16000 ;
Expenditure on food = 3x/10 = 3 x 16000 /10= ? 4800
Expenditure on conveyance = x/8 = 1 x 16000/8 = ? 2000
? Expenditure on food and conveyance together
=? (4800 + 2000) = ? 6800



Solution 2 .

part of income left
= 1 - (2/5 + 3/10 + 1/8 )
=1- (16 + 12 + 5/40)
= 1- 33/40 = 40 - 33/40 = 7 /40
Let the monthly income = x
According to the question,
7/40 x = 2800
? x = 2800 x 40/7
= 400 x 40 = ? 16000
Expenditure on food = 3/10 x 16000 = ? 4800
Expenditure on conveyance = 1/8 x 16000 = ? 2000
? Expenditure on food and conveyance together
=? (4800 + 2000) = ? 6800

Let first, second and third numbers be x , y and z, respectively.
Then , xy = 42.................(i)
yz = 56 ..................(ii)
xz = 48 ....................(iii)
Multiplying Eqs ( i), (ii) and (iii), we get
(xyz)² = 42 x 56 x 48
? (xyz)² = 112896
? xyz = 336 ................(iv)
Dividing Eq. (iv) by Eq. (i), we get
xyz/xy = 336/42 ? z = 8

Let the total amount = x
According to the question.
14 girls are getting x amount.
1 girl will get x/14 amount.
Similarly if
18 girls are getting x amount.
1 girl will get x/18 amount.
according to question,
x/14 - x/18 = 160
? (9x - 7x)/126 = 160
? 2x/126 = 160
? x/126 = 80
? x = 126 x 80 = ? 10080

Solution 1 :
Let the number of ? 50 notes = x, then the number of ? 100 notes = (170 - x)
According to question.
50x + 100(170 - x) = 10000
divide by 50 the above equation, we will get
? x + 2(170 - x) = 200
? x + 340 - 2x = 200
? -x = 200 - 340 = -140
? x = 140
? Required amount ? 50 x 140
= ? 7000


Solution 2 :
Let the number of ? 50 notes = x and the number of ? 100 notes = y.
according to given question,
x + y = 170 .............(1)
50x + 100y = 10000............(2)

Divide the equation (2) by 10 , we will get
5x + 17y = 1000............(3)
Multiply the equation (1) by 5
5x + 5y = 850 ------------(4)
Subtract the (4) equation from (3) equation, we will get,
5x +10y - ( 5x + 5y ) = 1000 - 850
? 5x +10y - 5x - 5y = 1000 - 850
? 10y - 5y = 1000 - 850
? 5y = 150
? y = 150/5
? y = 30
Number of ? 100 notes = y = 30;
since x + Y = 170
therefore x = 170 - y
? x = 170 - 30
? x = 140
Number of ? 50 notes = x = 140

Let the worker remains absent for x days.
Then, his working days = (120 - x) days.
According to the question,
20 x Working day - 3 x Absent day = 560
20(120 - x) - 3x = 560
? 2400 - 20x - 3x = 560
? x = 2400 - 560/23 = 1840/23
= 80 days

Let total number of apples in the crate = a
Then, number of bruised apples = a/40 .
Number of unsaleable apples
since 4 bruise apples containing 3 unsaleable apples.
therefore 1 bruise apples will contain 3/4 unsaleable apples
hence a/40 bruise apples will contain 3/4 x a/40 unsaleable apples
= 3/4 x a/40 = 3a/160
According to the question.
3a/160 = 9
? a = 9 x 160/3
a = 3 x 160 = 480

Let population of cities A and B become equal after x year.
According to the question.
Population of city A = Population of city B
Then,
136000 - 2400 x = 84000 + 1600 x.
? 4000x = 52000
? x = 52/4 = 13 year