Q:) Rahul had some bananas and he divided them into two lots A and B. He sold the first lot at the rate of ₹ 2 for 3 bananas and the second lot at the rate of ₹ 1 per banana and got a total of ₹400. If he had sold the first lot at the rate of ₹ 1 per banana and the second lot at the rate of ₹ 4 for 5 bananas, his total collection would have been ₹460. Find the total number of bananas he had.
Solution: Let Rahul have bananas in first lots = x
And Let number of bananas in second lots = y
First condition
Amount of money for lot A =
Amount of money for lot B = 1.y
Multiply by 3 in equation
⇒ 2x + 3y = 1200 —— (i)
Secon condition
Amount of money for lot A = 1.x
Amount of money for lot B =
Multiply by 5 in equation
5x + 4y = 2300 —–(ii)
Multiply by 5 in (i) and 2 in (ii) and substracting (i) to (ii)
5(2x + 3y) – 2(5x + 4y) = 1200 – 2300
⇒ 10x + 15 y – 10x – 20y = -1100
⇒ – 5y = -1100
⇒ y = 220
Putting the value of x in (i)
2x + 3×220 = 1200
⇒ 2x = 1200 – 660
⇒ 2x = 540
⇒ x = 540/2 = 270
Number of bananas in lot A = 270
Number of bananas in lot B = 220
https://gmath.in/ruhi-invested-a-certain-amount-of-money-in-two-schemes/