Question

Shalinital boucht some articles each costing rs.150 and some other articles
cach costing rs.180. In all she spend 3000 for buying 27 articles. How many
articles did she buy costing rs. 80?
plzz give me step by step explanation​

Answer 1

Answer:

The number of articles costing rs 80 is 3 .

Step-by-step explanation:

The total number of articles bought = 27

The total amount of money spend by Shalinital = Rs 3000

Let The number of article costing Rs 50 = x

The number of article costing Rs 80 = y

According to question

Total number of articles bought = 27

i.e x + y = 27             ............A

Again

Total amount of money spend by Shalinital = Rs 3000

i.e Rs 50 × x + Rs 80 × y = Rs 3000

Or, 50 x + 80 y = 3000                     ...........B

Solving eq A and B , we get

(50 x + 80 y) - 50 × (x + y) = 3000 - 50 × 27

Or, (50 x - 50 x) + (80 y - 50 y) = 3000 - 1350

Or, 0 + 30 y = 1650

∴  x = $\frac{1650}{30}$

i.e  x = 55

Put the value of x in eq B

∵ 50 x + 80 y = 3000

Or, 5 x + 8 y = 300

8 y = 300 - 5 × 55

Or, 8 y = 300 - 275

Or, 8 y = 25

∴  y = $\frac{25}{8}$

i.e y = 3.125 ≈ 3

So, The number of articles costing rs 80 = 3

Hence, The number of articles costing rs 80 is 3 . Answer