Question

Ranjana's mother gave her rupees 245 for buying new year cards .if she got some 10-rupee card  ,2/3 as many 5 rupees cards, and 1/5 as many 15-rupee cards, how many of each kind did she buy?

Answer 1

let number of 10 rupees cards = x
           cost of 10 rupees card = 10x
       number of 5 rupees cards = 2x/3
            cost of 5 rupees card = 5(2x/3) = 10x/3
     number of 15 rupees cards = x/5
            cost of 10 rupees card = 15(x/5) = 3x

total cost = 10x + 10x/3 + 3x = (30x+10x+9x)/3 = 49x/3
thus 49x/3 = 245
⇒x = (245×3)/49 
⇒x = 15 (no. of 10 rupees card)
2x/3 = (2×15)/3 = 10 (no. of 5 rupees card)
x/5 = 15/5 = 3 (no of 15 rupees card)

Answer 2

Answer:

Step-by-step explanation:

let number of 10 rupees cards = x

          cost of 10 rupees card = 10x

      number of 5 rupees cards = 2x/3

           cost of 5 rupees card = 5(2x/3) = 10x/3

    number of 15 rupees cards = x/5

           cost of 10 rupees card = 15(x/5) = 3x

= 10x + 10x/3 + 3x = (30x+10x+9x)/3 = 49x/3

49x/3 = 245

= (245×3)/49 

= 15 (no. of 10 rupees card)

2x/3 = (2×15)/3 = 10 (no. of 5 rupees card)

x/5 = 15/5 = 3 (no of 15 rupees card)