******************** -

[ -* am={(t s) d}

(am)= (t) (s) (d)

60 7 : 3 3:7 ?# am={(t s) d}=(60 3) (7-3)=204=80()---------------------------------------( -* [am=w (r1 + r2)] (am)= (w) (r1 + r2)

Question: 16 = 3:1 4:1 (17 21 10 )

#am={w (r1 + r2)}={16 (3+1)}=164=4()--------------------------------------------*********** ************ -[ - -*-[C=100 R 100 + t r]]

/(C)={100 (R)(100+(t) (r)}

Question: 5% 20 - 50,000 ?

# C=(100 R) (100 + t r)=(100 50,000) {100 + (205)}=5000000 200=25,000 ()--------------------------( ) ..... ---------------------------------------[Posted by:(Riyad Sawkat)]

Bangladesh Bank Written Math Solutionexam date: 15.05.2015A. A shop stocks 4 types of caps, there are 1/3as many red caps as blue caps and 1/2 as manygreen caps as red caps. There are equal numberof green caps and yellow caps.If there are 42blue caps, then what percent of the total caps inthe shop are blue?Soln :Blue caps = 42Red caps = 42/3 = 14Green caps = 14/2 = 7Yellow caps = 7Total caps= 42+14+7+7 = 70Percentage of Blue caps in total caps= 42/70 100 = 60%. (Ans).B. The annual incomes and expenditures of aman and his wife are in the ratio 5:3 and 3:1respectively. If they decide to save equally andfind a balance of tk. 4000 at the end of the year,what was their income?We know,Income = Expenditure + Income(Ratio of INCOMES and Ratio of EXPENDITURESare given)Let, Income :Man = 5xWife = 3xExpenditure,Man = 3yWife = ySo, Savings :Man = 5x - 3yWife = 3x - yCondition 1 :Their savings contribution is equal.So, 5x - 3y = 3x - yOr, x = yCondition 2 :Their total savings = 4000So, 5x - 3y + 3x - y = 4000Or, 5x - 3x + 3x - x = 4000Or, 4x = 4000So, x = 1000Therefore, Income :Man = 5 1000 = 5000Wife = 3 1000 = 3000. (Ans).C. A person sold 2 articles, each for the sameprice of tk. 1040. He incurred 20% loss on the1st item and 10% loss on the 2nd item. Find hissoverall percentage of loss?Soln : Given that,CP of 1st article 0.80 = 1040So, CP of 1st article = 1040100/80= 1300 tkCP of 2nd article 0.90 = 1040So, CP of 2nd article = 1040100/90= 1155.55 tkTotal CP = 1300+1155.55 = 2455.55Total SP = 1040+1040 = 2080------------------------------------------Overall loss = 375.55 tkOverall loss percentage= 375.55/2455.55 100= 15.29%. (Ans)D. If the sum of 5 consecutive integers is S,what is the largest of those integers in terms ofS?Soln :Let, the 1st number be xAtQ,x + (x+1) + (x+2) + (x+3) + (x+4) = SOr, 5x + 10 = SOr, x = (S - 10)/5Therefore, the largest number= x + 4= (S - 10)/5 + 4= (S - 10 + 20)/ 5= (S + 10) /5= S/5 + 10/5= S/5 + 2. (Ans).E. The difference between two numbers is 5 andthe difference of their squares is 65. What is thelarger number?Let, Two numbers be x & yConditions :1. x - y = 52. x^2 - y^2 = 65Or, (x + y) (x - y) = 65Or, (x + y) 5 = 65So, x + y= 13.x + y = 13x - y = 5-------------2x = 18,x = 9.Now, putting the value of x in Condition 1, weget,9 - y = 5y = 4Therefore, the larger number is 9. (Ans)F. Robi drove 100 miles to visit a friend. If hehad driven 8 mph faster than he did, he wouldhave arrived in 5/6 of the time, he actually took.How many minutes did the trip take?Soln :We know,Speed = Distance / TimeUsually, Let,S = 100 / tNow,S + 8 = 100 / (5t/6)or, 500 + 40t = 600Or, t = 100/40Or, t = 2.5 hoursOr, t = 2.5 60 minsSo, t = 150 mins . (Ans).G. (2+x+2-x) / (2+x-2-x) = 2Or, (2+x+2-x) / (2+x-2-x) = (3+1) / (3-1)Or, 2+x / 2-x = 3/1 (-)Or, {2+x / 2-x }^2 = 3^2 ( )Or, (2 + x) / (2 - x) = 9Or, 10x = 16So, x = 8/5. (Ans)H. Of the 3 nemumbers, 2nd is twice the 1st andthrice the third. If the average of the 3 numbersis 44, then what will be the largest number?Soln : Let,1st Number = x2nd Number = 2x3rd Number = 2x/3ATQ,x + 2x + 2x/3 = 44 3Or, 3x + 6x + 2x = 44 3 3Or, x = 36So, the largest number is= 2 36 = 72. (Ans).#//// ,,,/ / / / // // / /,, ------------------------------------------ #Mp3_________)

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