Important word problems on Linear Equations in two variables 3
Question for practice
The following questions are more helpful for class tenth students for all boards.
Questions 3. A sum of Rs. 41 was divided among 50 boys and girls. Each boy gets 65 paise and each girl 90 paise. Find the number of boys and girls.
Submit your answer here in the comments or wait for answer
Ans. Let no.of boys = x
ReplyDeleteLet no. of girls = y
x+y = 50 ......(1)
0.65x+0.9y = 41 .....(2)
by elimination from (1) and (2),
x = 16
y = 34
therefore, No. of boys = 16
No. of girls = 34
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ReplyDeleteLet numbers of boys = b
ReplyDeleteLet numbers of girls = g
(1)...... b+g = 50
(2)...... 0.65b+0.9g = 41 [1 rs = 100 p ]
by elimination from (1) and (2),
b = 16
g = 34
therefore, Numbers of boys = 16
Numbers of girls = 34
let the number of boys be x
ReplyDeletelet the number of girls be y
x+y = 50 (1)
65x+90y = 4100
=> 13x+18y = 820 (2)
from (1) and (2) , by elimination y = 34
therefore, x = 16
Hence, the number of boys = 16 and number of girls = 34
let the number of boys be x and the number of girls be y.
ReplyDeletetherefore,
x+y=50(1)
and
0.65x+0.90y=41
or
65x+90y=4100
13x+18y=820(2)
from (1) and (2) by elimination we get
x=16
y=34
therefore,
the number of boys=16
the number of girls=34
let no. of boys be x
ReplyDeletelet no.of girls be y
x+y = 50 ----(1)
65x + 90y = 4100 -------(2)[Re.1=100P]
by elimination method
y=34 (no. of girls)
x=16 (no. of boys)
let the number of boys be b
ReplyDeleteand number of girls be g
we know, b+g=50 ( number of boys and number of girls) equation 1
0.65b + 0.90g=41
OR
0.65b + 0.90g=41*100
=>65b + 90g=4100 equation 2
subtracting eq. 1 from eq.2 i.e.
b + g = 50*90
65b + 90g = 4100
- - - ( sign changes)
=> 90b + 90g = 4500
so, 90b + 90g =4500
65b + 90g = 4100
(-) (-) (-)
_____________________
25b = 400 ( since 90g and 90g got cancelled , we left with)
b = 400/25 = 80/5 = 16
= b = 16
putting this value in equation 2
65(16) + 90g = 4100
1040 + 90g = 4100
90g = 4100 - 1040 = 3060
90g = 3060
g = 3060/90 = 102/3 = 34
=> g = 34
so , number of girls = 34
and number of boys = 16
Let the no. of boys = x
ReplyDeleteLet the no. of girls = y
So, x + y = 50
=> 13x + 13 y = 650........(1)
Also, 65x/100 + 90y/100 = 41
=> 65x + 90y = 4100
=> 13x + 18y = 820........(2)
Eliminating (1) and (2), we get
y = 34 and x = 16!!!
THANKS!!!