Question

The average of the sales of an electronics shop in the years 1991, 1992, 1993 and 1994 is 2000, and that for the years 1992, 1993, 1994 and 1995 is 2200. If the sales in 1995 are 1800, find the sales in 1991.

• A. 800
• B. 1200
• C. 1000
• D. 500

Answer 1

Answer:

C. 1000

Let the sales be:
1991 = (a), 1992 = (b), 1993 = (c), 1994 = (d), 1995 = 1800

First average (1991–1994)

$\frac{a+b+c+d}{4} = 2000$
a+b+c+d = 8000

Second average (1992–1995)

$\frac{b+c+d+1800}{4} = 2200$
b+c+d+1800 = 8800
b+c+d = 7000

Find (a)

Subtract:
$(a+b+c+d) - (b+c+d) = 8000 - 7000$
a = 1000

Final Answer:

Sales in 1991 = ₹1000