Question

A, B, C
AND O
ARE FOUR NUMBERS IN ARITHMETIC
PROGRESSION. THE MEAN OF THESE FOUR NUMBERS IS 20.
THE COMMON DIFFERENCE BETWEEN THE NUMBERS is 5.
FIND THE PRODUCT OF FIRST AND LAST NUMBERS ?​

Answer 1

Answer:

Step-by-step explanation:

AP

Common difference is 5

Mean of 4 numbers is 20

Let four numbers be

X X+ 5 X+10 X+15

Sum of 4 numbers = 4X+30

Mean of 4 numbers =( 4X+30 )/4

Given mean of 4 numbers is 20

Hence 4X+30 =4×20

4X = 80-30=50

X=50/4=12.5

Product of last and first numbers is X × X+15

=12.5 ×(15+12.5)

12.5 × 27.5 =343.75