1.  The prices of two articles are as 3 : 4. If the price of the first article is increased by 10% and that of the second by ₹ 4, one original ratio remains the same. The original price of the second article is :
A. ₹ 40
B. ₹ 10
C. ₹ 30
D. ₹ 35

Answer: Option A

Explanation:

Let cost price of two articles be 3x and 4x, respectively.
Then,

Reduction in consumption

= 110% of 3x % = 3/4
4x + 4

1.1x   = 1.
x + 1

1.1x = x + 1

0.1x = 1

x = 10

Thus, cost price of the second article is : 4 x 10 = ₹ 40