Question

1 15 3 21 6 28 ? What number should replace the question

Answer 1

Answer:

10

Step-by-step explanation:

1,3,6,10 is a series

Answer 2

Step-by-step explanation: take the first number 1 add 2 and you get 3rd number 3 add 3 and you get 5th number 6, So if you skip 28 you should add 5th number by 4 so 6+4 = 10 so ? = 10 and 10 + 5 = 15, 15 + 6 = 21, 21 + 7 = 28.

So basically you have to skip 1 number and add 2 and skip and go to the next number and add 3 and skip and go add 4, so like that you get 10 and you need to skip 6 after you get 10 and add 5 so you get 15 and skip and add 6 and skip and add 7.