Suresh kumar went to the market with 100 rs if he buys three pens and 6 pencils he uses up all his money but if he buys three pencils and 6 pens he falls short by 20% if he wants to buy equal no. Of pens and pencils how many pencils can he buy?
Answers
Answer:
he can buy 4 pencils
Step-by-step explanation:
3pens + 6 pencils costs 100rs
if he buys 3 pencils + 6 pens shortage of 20% means it costs 120rs
6 pencils + 3 pens = 100 ⇒ 2pencils + 1 pen = 100/3
3 pencils + 6 pens = 120 ⇒ 1pencil + 2 pens = 40
by multiplying 1st equation with 2 and substracting 2nd equation from 1 we get
4 pencils + 2pens = 200/3
-1pencil - 2pens = - 40
3pencils = 200/3 - 40 = 80/3
1 pencil = 80/9 = 8rs
2pens = 40 - 8.888 =31rs
1 pen=15rs
suppose if he buys each of 2
2*8+2*15=16+30=46
each of 3
3*8+3*15=24+45=69
each of 4
4*8+4*15=32+60=92
Answer:
the buyer can buy 4 pens and 4 pencils in 100 rupees.
given:
Cost of 3 pens and 6 pencils = 100 rupees
if he buys three pencils and 6 pens he falls short by 20%
To Find:
If he wants to buy equal no. of pens and pencils how many pencils can he buy in 100 rupees
Step-by-step explanation:
Cost of 3 pens and 6 pencils = 100 rupees
if he buys three pencils and 6 pens he falls short by 20%
100 = 0.8 cp
cp = 125 rupees
means , cost of 6 pens and 3 pencils = 125 rupees
Let the cost of pen = x rupees
Let the cost of pencil = y rupees
according to the question,
3 x + 6y = 100
6x + 3y =125
Solving above equations we get
x = 50/3 , y 25/3
so according to the question , we have to buy equal number of pens and pencils
n ( x + y ) = 100
n ( 50/3 + 25/3) = 100
n(75) = 300
n = 300/75
n = 4
Hence the buyer can buy 4 pens and 4 pencils in 100 rupees.