A man wants to invest total Rs. 3900 in account of his two sons who are 14 years and 16 years old in such a way that they will get equal amount at the time of attaining the age of 18 years. If rate of interest per annum is 10% then find the amount he has to deposits in account of his younger son.
Answer & explanation
Correct answer: option 4
Let the share of younger and elder son is P1 and P2 respectively.
Time for younger son = 18 - 14 = 4 years
Time for elder son = 18 - 16 = 2 years
effective R% for younger son = 4 × 10 = 40%
effective R% for elder son = 2 × 10 = 20%
ATQ,
P1 × \(\frac{140}{100}\) = P2 × \(\frac{120}{100}\)
\(\frac{P_1}{P_2}\) = \(\frac{6}{7}\)
P1 : P2
6 : 7 = 13
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×300 ×300
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1800 3900