Solution Let, Sapna's monthly income is Rs. 100 Given information, Sapna invests her monthly income in mutual Fund = 18% And she invests in mutual funds = Rs. 5,724 Then, 18% = 5,724 1% = 5,724 / 18 1% = 318 Now, 100%= 318 x 100 = 31,800 So, Sapna's monthly income will be 31,800. Hence, "31800" is the correct answer.