Question:
A number is divided into two parts in such a way that 80% of 1st part is 3 more than 60% of 2nd part and 80% of 2nd part is 6 more than 90% of the 1st part. Then the number is-
A115
B125
C135
D145
Answer:
C. 135
Explanation:
First part = Rs. x and second part = Rs. y 80% of x = 60% of y + 3 80x/100=60y/100 + 3 80x-60y=300 4x-3y=15---------- (i) 80% of y = 90% of x + 6 80y/100=90x/100 + 6 80y-90x=600 8y-9x=60----------(ii) Multiply (i) × 8 + (ii) × 3 32x – 24y = 120 24y – 27x = 180 Solving these equations, 5x = 300 , x = 60 , y = 75 Number=60+75=135