Question

There are four numbers. Average of the first three is 15 and that of the last three is 16. If the last number is 19 find the first number:

Answer 1

hi friends here is yours answer

average of first 3 =15

sum of 1st 3 no. = 3×15=45

& also last 3 no. =16

sum of last 3 =16×3=48

in it last no is 19

so middle two =48-19=29

so 29 minus from first 3

so 1st no =45 -29

1st no. =16

so

let 2nd no be x and 3rd be 29 -x

so

according to the 1st conditions

16 +x+29 -x =45

x + 29 - x = 29

let x be 15

so 3rd no be 14

this your answer

Answer 2

Answer:

Step-by-step explanation:

➡️ average of first 3 =15

sum of 1st 3 no. = 3×15=45

& also,

➡️ last 3 no. =16

sum of last 3 =16×3=48

in it,

➡️ last no is 19

so middle two =48-19=29

so 29 minus from first 3

so 1st no =45 -29

1st no. =16

so,

let 2nd no be x and 3rd be 29 - x

according to the 1st conditions

=> 16 +x+29 -x =45

=> x + 29 - x = 29

let x be 15

so 3rd no be 14 ans.