Answer:
Step-by-step explanation:
rather than doing all of the sums, you should just learn the formula (for the pattern)
it is n(highest + lowest) where n is number of numbers
2
for example 2+3+4+5+6 = 20
5(6+2) = 20
2
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1+2+3+4+5+6+7+8 = 36
8(9) = 72/2= 36
2
