26 May Maths Ii

MATHS Dr. T.K. Jain. AFTERSCHOOOL M: 9414430763 [email protected] www.afterschool.tk www.afterschoool.tk

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Goods were bought for Rs. 600, and sold immediately at Rs. 650.25 at a credit of 9 months. There is gain of 2%, what is interest rate? • Gain is 2%, that means, on 600, we earn Rs. 12. but we are getting 650.25, that means, the present value of 650.25 is 612. the typical formulae is : TD = PW*R*T/100, using this formulae – • Time = 9/12 = .75; 38.25=612*R*.75/100, by this we can get R. = 3825/612*.75 = 3875/459 =8.44 Ans. www.afterschoool.tk

My material and other costs are in the ratio 2:3. my material cost is Rs. 200. I charge 20% margin. Someone purchased from me at Rs. 675. My interest rate is 9%. Can you tell what is my credit period? • My cost is 500, + margin = 100, present worth = 600. TD=PRT/100 • 75=600*9*T/100;, T=7500/600*9 = 17 months approx. www.afterschoool.tk

A has to pay Rs. 220 to B after 1 year. B asks A to pay Rs 110 in cash and defer the payment of Rs. 110 for 2 years. Interest rate is 10%, what is the gain / loss to B in present terms?

• Present value of 220 is Rs. 200. So A should have paid Rs. 200 today. But he has paid only 110. that means the remaining amount is Rs. 90. B is getting 110 for Rs 90 of today. The present value of it is : formulae of PW = 100*Amt / ((R*T)+100)= 100*110/[(10*2)+100] = 91.66. the gain of B is Rs. 1.66 today. www.afterschoool.tk

A park is 14 feet long and 12 feet wide. It has a 2 feet walking space in all four sides of it. What is the maximum length of pole that can we put in this park (maximum length) which should not come into walking space?

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We have to calculate here – diagonal Length = 14-2-2 = 10 Width = 12-2-2- = 8. Diagonal of 10 and 8 = square root of 100+64 = 12.8 Ans. www.afterschoool.tk

What is the cost of painting a design which is equilateral triangle in shape. The cost of painting is Rs. 6 per square meter. One side of this design is 6 meters. • Formulae is 3^1/2 /4 *side*side • =3^1/2 /4 (6*6) multiply this by 6 • =Rs. 93.5 Ans. www.afterschoool.tk

I have to carpet AFTERSCHOOOL class room. Carpet is Rs. 8 per meter (75 cm. wide). Diagonal of my room is 13 and length of my room is 12 meters. What is my total cost. • First calculate area of room. Length is 12, width is : sqrt of (13^2 – 12^2) = 5, Area is 60 Sq. meters. Width of carpet is .75, so we will need 60/.75 = 80 meters of carpet – cost =80*8=640Rs. Ans. www.afterschoool.tk

HCF of two numbers is 99, LCM is 2772, what are the numbers? • step:1 divide 2772 by 99=28. • Now take factors of 28. these are 2*2*7. Now take two different sets of factors – so we take 2*2 and 7 and multiply these by 99. • First number is 99*4 = 396, • Second number is : 99*7 = 693 Ans. www.afterschoool.tk

What is the least number, when divided by 20, 32 and 45 leave remainder of 8,20 and 33 respectively? • First calculate LCM of 20,32 and 45. • Factors of 20 are : 4*5, for 32:4*8, for 45:5*9 • So number is 4*5*8*9=1440. • Since remainder in each case is 12 less then the number, so we will deduct 12 from this: 1440-12 = 1428. Ans www.afterschoool.tk

What is the greatest number which will divide 129, 631 and 1033 and will give remainder of 4, 6 and 8 respectively? • Step 1: deduct these remainders from these numbers, so the numbers are : 125,625,1025. • Now find HCF of these number is 25, so answer is 25. Ans.

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What is HCF of ¼, 3/7, 5/8? • When we have to calculate HCF of fractions, take HCF of Numerators and take LCM of denominators. • So HCF of 1,3,5 is 1. • LCM of 4,7 and 8 is : 56. • HCF is 1/56 Ans.

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What is LCM of ¼, 3/7, 5/8? • When we have to calculate LCM of fractions, take LCM of Numerators and take HCF of denominators. • So LCM of 1,3,5 is 15. • HCF of 4,7 and 8 is : 1. • LCM is 15/1 = 15 Ans.

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Thanks Afterschoool conducts three year integrated PGPSE (after class 12 along with IAS/CA & CS) and 18 month PGPSE (Post Graduate Programme in Social Entrepreneurship) along with preparation for CS / CFP / CFA /CMA / FRM. This course is also available online also. It also conducts workshops on social entrepreneurship in schools and colleges all over India – start social entrepreneurship club in your institution today with the help from afterschoool and help us in developing society.

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