Question

The average of 5 numbers is 88.6. If average of last 4 numbers is 77.5. Find the first number.

Answer 1

Answer:

25

Step-by-step explanation:

Sum of 6 numbers =60×30=180

Sum of first 4 numbers =4×25=100

Sum of last 3 numbers =3×35=105

∴ Fourth number =(100+105)−180

                              =205−180

                              =25