Instructions? "Find the number."
12 + 5n = 9n
12 = 4n and so n = 3 (answer)
What 2 numbers whose sum is 105.7 the numbers are 19, 85.2, 533, 571, 88.2, 525, 20, 17.5, 400, 261, 20.5 ,125, 7, 23, 901, 30
givi [52]
To make it quickly we can consider only those numbers which will give us a decimal of xxx.7. There are only a few numbers like this: 85.2, 88.2, 20.5.
I tried adding 85.2 to 17.5 and it gave me 102.5 - it was close but not close enough :)
So I picked 85.2 + 20.5 = 105.7 and voila :)
Answer:
(2+5)2-52
=7× 2-52
=14-52
= -42
not in this list but that's right answer
