What is the next number in the sequence?

23  35  47  59  ?First we need to find the pattern in the sequence. We can do this by working out the gaps between the numbers. To work out the gap, we subtract each number from the next one in the sequence.35 - 23 = 1247 - 35 = 1259 - 47 = 12Now we know the pattern is that each number is bigger than the last by 12.So all we have to do to find the next number in the sequence is add 12 to the previous number, which is 59.59 + 12 = 71So the next number in the sequence is 71!