Question

The average footfall of customers in a Multiplex for Monday, Tuesday and Wednesday was 844, whereas the average for Tuesday, Wednesday and Thursday for the same week was 826. If the footfall for Thursday was 780, then what was the footfall of customers on Monday? 
1. 758
2. 824
3. 772
4. 834

Answer 1

Correct Answer - Option 4 : 834

Given:

Average footfall of customers for Monday, Tuesday and Wednesday = 844

Average footfall of customers for Tuesday, Wednesday and Thursday = 826

Footfall for Thursday = 780

Calculation:

Let us denote the footfall of customers in the Multiplex for Monday, Tuesday, Wednesday and Thursday be Mo, Tu, We & Th.

According to the question,

Average footfall of customers for Monday, Tuesday and Wednesday = 844

⇒ (Mo + Tu + We)/3 = 844

⇒ Mo + Tu + We = 3 × 844

⇒ Mo + Tu + We = 2532      ----(i)

Again,

According to the question,

Average footfall of customers for Tuesday, Wednesday and Thursday = 826

⇒ (Tu + We + Th)/3 = 826

⇒ Tu + We + Th = 3 × 826

⇒ Tu + We + Th = 2478      ----(iI)

Subtracting equation (i) from equation (ii),

(Mo + Tu + We) - (Tu + We + Th) = 2532 - 2478

⇒ Mo + Tu + We - Tu - We - Th = 54

⇒ Mo - Th = 54

⇒ Mo = 54 + Th

⇒ Mo = 54 + 780

⇒ Mo = 834

∴ The footfall of customers in the Multiplex on Monday was 834.