The average price of three items of furniture is Rs 15990. If their prices are in the ratio 3:5:7, the price of the costliest item (in Rs) is

Correct option is C

Given: 

Average Price of 3 item = ₹15990.

3 item's price ratio = 3 : 5 : 7 

Formula Used: ​

Average = $$\frac{\text{Sum of values}}{\text{number of values}}$$

Solution: ​

Let the price of items be 3x, 5x, 7x 

Total Price of 3 items = $$15990 \times 3 = 47970$$

So, 

3x + 5x + 7x = 47970

15x = 47970

x = $$\frac{47970}{15} = 3198$$

Price of costliest item = $$7 \times 3198= \text{Rs.}22386$$