SBI PO Quantitative aptitude practice set 26

1 . A 380-metre-long train running at a speed of 80 kmph will take how much time to cross another 420-metrelong train running in opposite direction at a speed of 48 kmph? A.   20.12 seconds B.   22.5 seconds C.   20.5 seconds D.   18.57 seconds 2 . How many kilograms, of sugar at Rs.42 per kg should a man mix with another 25 kg of sugar at Rs.28 per kg so that he may gain 25% profit by selling Rs.40 per kg? A.   8 kg B.   15 kg C.   20 kg D.   10 kg 3 . A number X is increased by 20% to get another number Y. A third number Z is obtained by increasing Y by 10%. By what per cent should Z be decreased to get X? A.   26.51% B.   24.24% C.   28.36% D.   31.71% 4 . Z can do a piece of work in 42 days. Y can do the same piece of work in 36 days. W can do it in 56 days. Z worked for 18 days and handed it to Y, who worked for 9 days and left the job for W. How many days will W take to finish the work? A.   16 days B.   20 days C.   24 days D.   18 days 5 . Munsi Premchand sold a cow at a loss of 15%. Had he sold it for `300 more he would have earned a profit of 10% instead of loss. Find the cost price of the cow. A.   1200 B.   1250 C.   1100 D.   1400

Answers & Solutions   1 .     Answer : Option C Explanation : Reqd time = $Length of train A + Length of train Bover Speed of train A + Speed of train B$ = $800 times 18 over 128 times 5$ = 22.5 seconds 2 .     Answer : Option D Explanation : Selling price of 1 kg mixture = Rs.40 per kg profit = 25% Cost price of 1 kg mixture = 40 x $100 over 125$ = Rs. 32 per kg 3 .     Answer : Option B Explanation : y = $x$ x $120 \over 100$ = $6x\over 5$ z = y x $110\over 900$ = $11y\over 10$ = $11 \over 10$ x $6\over 5$$x$ = $66 \over 55$$x$ Reqd % = ${66 \over 50}x - x \over {66\over 50}x$ x 100 = 24.24 % 4 .     Answer : Option D Explanation : Work of Z in 1 day = $1\over 42$ Work of Z in 18 days = $18 \over 42$ = $3 \over 7$ Work of Y in 1 day = $1\over 36$ Work of Y in 9 days = $9\over 36$ = $1\over 4$ Work of W in 1 day = $1\over 56$ Remaining work = 1 - ($3\over 7$ + $1 \over 4$) = $28 - (12 + 7) \over 28$ = $9 \over 28$ Now , W will take 56 x $9 \over 28$ = 18 days to finish the work. 5 .     Answer : Option A Explanation : Let the cost price of cow be Rs. X Selling price at 15 % loss = $x$ x $85 \over 100$ x = $300 \times 100 \over 25$ = Rs.1200