Fractions and Decimals
There are two fractions such that fraction X is thrice the fraction Y and their product is 25/12. Which of the following is equal to Y?
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.
Let the length of lamppost = L mThen,first part = L/3and second part = (3/8) x L/3 = L/8 and third part = 6 m 50 cm = 6.50 mFirst part + second part + Third part = length of lamppost ⇒ L/3 + L/8 + 6.5 = L ⇒ L - L/3 - L/8 =6.5 ⇒ (24L - 8L - 3L)/24 = 6.5 ⇒ 13L/24 = 6.5 ∴ L = (65.x 24)/13 = 12 m
Time required for service before overhauling = 2/3h = 40 min in 45 days and time required for service after overhauling =2/3h= 40 min in 60 days Now,LCM of 45 and 60 = 180 days time required for service before overhauling is 180 days = 40 x 4 = 160 min and time required for service before overhauling is 180 days =40 x 3 = 120 min ∴ fraction of time saved = 160 - 120/160 =40/160 = 1/4