Question

A company placed an order for 20 high-end laptops and some quantity of standard desktops. The price of a high-end laptop was 5 times that of a standard desktop. Due to a mistake, the number of laptops and desktops was interchanged in the delivery. This caused the total bill to increase by 80%. What was the ratio of the number of high-end laptops to standard desktops in the original order?

• A. 1 : 2
• B. 2 : 1
• C. 5 : 2
• D. 2 : 5

Answer 1

Answer:

D. 2 : 5

Let the price of one standard desktop be ₹1.

Then price of one high-end laptop = ₹5.

Original order:

• 20 laptops

• (x) desktops

Original bill:

$20(5)+x(1)=100+x$

By mistake, quantities were interchanged:

• (x) laptops

• 20 desktops

New bill:

5x+20

Given that the new bill increased by 80%:

$5x+20=1.8(100+x)$

Solve:

5x+20=180+1.8x
3.2x=160
x=50

So, the original numbers were:

• Laptops = 20

• Desktops = 50

Required ratio:

20:50 = 2:5

Therefore, the ratio of high-end laptops to standard desktops was 2 : 5.