Question

I AM THINKING OF A NUMBER.IF THE SUM OF 2.45 AND 9.8 IS SUBTRACTED FROM IT,THE RESULT IS 8.21 .WHAT NUMBER AM I THINKING OF???

Answer 1

$let \: \: the \: \: no. \: \: be \: \: x \\ \: then \\ x - (2.45 + 9.8) = 8.21 \\ \\x - 12.25 = 8.21 \\ \\ x = 8.21 + 12.25 \\ \\ x = 20.46$