It does not mean anything at all. "Twice a number" is only one number while "the difference" must refer to two numbers, not just one.
The question cannot be answered because it is ambiguous. Does "twice the sum of 16 and a number" mean "2*16 + x" or does it mean "2*(16 + x)"
2 (N + 3)
This means that X=2N-3.
If you mean: 5, 10, 20, 40 then the following number is twice the previous number which will be 80
twice a number means a number times 2
Twice a number means to multiply the number by 2
Fifty Two
Three more than twice a number.
An event of some sort that happens twice a year.
I believe you mean molarity. Molarity is a unit of concentration. So if the number is twice as big...
18 is the only number (other than 0) that is twice the sum of its digits.
Let the number be x Twice a number means 2x 7 less than twice a number means 2x-7
2(n+3)
Twice the number n is 2n.
2x-5 is twice a number decreased by 5.
twice the difference of three times a number and eight