Rohit spent (R-4)% of his monthly income on food. Out of the remaining (R+7)% was spent on travelling. (1/6) of the remaining was spent on education. (2R–1)% of the remaining was spent on house rent and after that the remaining amount was saved by him. If the annual savings of Rohit is Rs. 402480, then find out the monthly expenditure on travelling. It is assumed that the monthly salary of Rohit is 1600 times of the difference between the both of the roots of ‘Y’.

(Y² - 540Y + 72000 = 0)

Solution

(Y² - 540Y + 72000 = 0) Y² - 540Y + 72000 = 0 Y² - (300+240)Y + 72000 = 0 Y² - 300Y - 240Y + 72000 = 0 Y(Y- 300) - 240(Y- 300) = 0 (Y - 300) (Y - 240) = 0 Y = 300, 240 It is assumed that the monthly salary of Rohit is 1600 times of the difference between the both of the roots of ‘Y’. monthly salary of Rohit = 1600x(300-240) = 1600x60 = 96000 Rohit spent (R-4)% of his monthly income on food. Out of the remaining (R+7)% was spent on travelling. (1/6) of the remaining was spent on education. (2R–1)% of the remaining was spent on house rent and after that the remaining amount was saved by him. If the annual savings of Rohit is Rs. 402480. 96000 of [100-(R-4)]% of [100-(R+7)]% of [1-(1/6)] of [100-(2R–1)]% = 402480/12 96000 x [100-R+4]% x [100-R-7]% x (5/6) x [100-2R+1]% = 33540 0.096 x [100-R+4] x [100-R-7] x (5/6) x [100-2R+1] = 33540 0.016 x [104-R] x [93-R] x 5 x [101-2R] = 33540 0.08 x [104-R] x [93-R] x [101-2R] = 33540 [104-R] x [93-R] x [101-2R] = 419250 (−R+18) (2R ² − 459R + 30979) = 0 So R = 18 Monthly expenditure on travelling = 96000 of [100-(R-4)]% of (R+7)% Put the value of ‘R’ in the above equation. = 96000 of [100-(18-4)]% of (18+7)% = 96000 of [100-14]% of 25% = 96000 of 86% of 25% = 96000 x (86/100) x (25/100) = Rs. 20640