Divide ₹ 2379 into 3 parts so that their amounts after 2, 3 and 4 years respectively may be equal, the rate of interest being 5\% per annum at simple interest. The first part is
(a)₹ 759
(b)₹ 792
(c)₹ 818
(d)₹ 828
Answer
Answer (as printed): D
Explanation
Let the parts be x, y and z. 5 5 5 x + x × 2× = y + y × 3× = z + z× 4× 100 100 100 11x 23 y 6 z 10 k 20 k 5k = = =k ⇒ x= ,y= ,z= . ⇒ 10 20 5 11 23 6 But x + y + z = 2379 10 k 20 k 5 k ⇒ + + = 2379 11 23 6 ⇒ 1380k + 1320k + 1265k = 2379 × 11 × 23 × 6 2379 × 11 × 23 × 6 3 × 11 × 23 × 6 ⇒ k= = 3965 5 10 3 × 11 × 23 × 6 x= × = 828. 11 5 Hence, the first part is ` 828.
Explanation as extracted from the printed page; notation may be imperfect.