In an engineering college the average salary of all engineering graduates from Mechanical trade is Rs 2.45 lacs per annum and that of the engineering graduates from Electronics trade is Rs 3.56 lacs per annum. The average salary of all Mechanical and Electronics graduates is Rs 3.12 lacs per annum. Find the least number of Electronics graduates passing out from this institute.

Let number of Electronic graduates be $$x$$ and number of mechanical graduates be $$y$$

According to ques,

=> $$3.56x+2.45y=3.12(x+y)$$

=> $$356x+245y=312x+312y$$

=> $$44x=67y$$

=> $$\frac{x}{y}=\frac{67}{44}$$

$$\because$$ 67 and 44 are co-primes, hence minimum value of $$x$$ and $$y$$ are 67 and 44 respectively. (Both must be integers)

$$\therefore$$ Minimum number of Electronic Graduates = 67

=> Ans - (C)