It is permissible for a fasting person to use miswaak and toothpaste whilst fasting, so long as he is careful not to swallow anything. In fact using the miswaak is Sunnah when fasting and otherwise.
First term : 4
Second term: 4+3 = 7
Third term : 7+5 = 12
Fourth term : 12+7 = 19.
Fifth term : 19+9 = 28.
Therefore,
Next Terms : 28+11 = 39
Let the number be x
Then,
⇒x+75% of x+25% of x3=240⇒x+75100x+25100x=240×3⇒x+34x+14x=720⇒2x=720⇒x=360