Question

I start with100 and subtract 3 repeatedly. (100-3,97-3,94- 3 and soon). How many subtractions would i have to do to get the first single-digit number?.

Answer 1

Step-by-step explanation:

You could start from 100 and keep on subtracting 3 until you hit a number that is less than 10.

That's the long way. You could use some algebra, and do the same thing

100 - 3n = start with -9 That would be the first possible single digit.

100 - 3n = - 9 Subtract 100 form both sides

- 3n = -9 - 100

-3n = - 109 -109 is not divisible (evenly) by -3

Start again

100 - 3n = - 8

-3n = - 108 That's the answer. Divide by -3

n = -108 / - 3

n = 36

So you would have to make 36 subtractions until you hit a result that is divisible by -3