Fractions and Decimals
A man spends (1/7)th of his salary on food, half of the remaining on clothing and (1/3)rd of the remaining on entertainment. He is still left with Rs. 600. How much does he spend on entertainment ?
Let man's salary be Rs. NMoney spend on food =N/7Money spends on clothing = (N - N/7) x 1/2 = (6N/7) x (1/2) =3N/7Money spend on entertainment = (N - N/7 - 3N/7)/3 = (7N - 4N)/7 = N/7Now, money left =600⇒ N - N/7 - 3N/7 - N/7 = 600⇒ 7N - 5N/7 = 600⇒ N = 600 x 7/2 = Rs. 2100∴ Money spend on entertainment = 1/7 x 2100 = Rs. 300
Let X and Y are given fractions.Given that, fraction X is thrice the fraction Y;i.e., X = 3Y ...(1)And their product = X x Y = 25/12Sub. eqn (1) in above,(3Y)x(Y) = 25/123(Y²) = 25/12(Y²) = 25/36Y = 5/6Hence the required fraction is 5/6.