Question

A pen and a notebook cost 270 together. four pens cost the same as five notebooks. find the cost of each

Answer 1

Answer:

Cost of one pen = X = rs. 150

Cost of one notebook = Y = rs. 120

Step-by-step explanation:

let cost of a pen rs. X

let cost of a notebook = rs. Y

According to question,

x+y = 270 ......(i)

4x = 5y

4x - 5y = 0 ......(ii)

LCM of 1 and 5 = 5

for making ,y = 5y, multiply by 5 in (i)

(x+y = 270 ) * 5

5x + 5y = 1350 ......(iii)

add (ii) and (iii),

(4x - 5y = 0) + (5x + 5y = 1350 )

9x = 1350

x= 1350 / 9

x = 150

putting value of X in (i)

150 + y = 270

y = 270 - 150

y = 120

Cost of one pen = X = rs. 150

Cost of one notebook = Y = rs. 120