২২৫৫১
A group of students decided to collect as many paisa from each from each member of a group as is th number of members. If the total collection amounts to Tk 59.29 , what is the m=number of members in the group?
উত্তর
77
সমাধান
Money collected = ( 59.29 ×100) paisa = 5929 paisa
No of numbers = root(5929) = 77
২২৫৫২
Selim deposited a total of taka 120,000 in two savings accounts for one year. One account offered him 8% interest and the other 10%. If he earned taka 10,000 as interest, how much did he deposit at 8%?
উত্তর
TK. 100,000
সমাধান
Let the amount deposited at 8% and 10% interest be X and (120000 - X) respectively.
Interest, I = P n r
Now, X × 1 × 8/100 + (120000 - X) × 1 × 10/100 = 10000 [total interest]
8X + 10(120000 - X) = 1000000 [multiplying both sides by 100]
or, 8X + 1200000 - 10X = 1000000
or, 10X - 8X = 1200000 - 1000000
or, 2X = 200000
So, X = 100,000 TK
২২৫৫৩
If the purchasing price of 15 apples and selling price of 12 apples are the same then how much is the gain in percentage form?
উত্তর
25%
সমাধান
Purchasing price of each apple = 1/15
Selling price of each apple = 1/12
Gain percentage = (1/12 - 1/15) / (1/15) × 100% = (5 - 4)/60 / (1/15) × 100% = 1/60 × 15 × 100% = 25%
২২৫৫৪
Farhana deposited TK.10,000 in a Bank at 13.25% interest rate compounded annually. At the end of the second year, the total amount including interest will become how much?
উত্তর
TK.12,826
সমাধান
C = P(1 + r/n)nt [C = principal with interest, P = principal, r = rate of interest, n = number of times interest is compounded per time period, t = number of time periods]
Here, P = 10000 TK, r = 13.25% , n = 1 , t = 2
C = 10000(1 + 13.25/100)1×2 = 10000 × 1.2826 = 12826 TK
২২৫৫৫
A can do a piece of work in 10 days. While B alone can do it in 15 days. They work together for 5 days and the rest of the work is done by C in 2 days. If they get Tk 450 for the whole work, how much money C should get from the whole?
উত্তর
Tk. 75
সমাধান
A এবং B এর 5 দিনের work = 5 ( 1/10 + 1/15) = 5/6
বাকি কাজ থাকে = 1 - 5/6 = 1/6
C এর 2 দিনের কাজ = 1/6
তাদের কাজের অনুপাত = 5/10 :5/15 : 1/6 = 3:2:1
তাহলে C এর টাকা = (450 × 1/6) = 75 টাকা।
২২৫৫৬
1 year ago the ratio between A's and B's sakary was 3:4. Rations of their individual salaries between last year's and this year's salaries are 4:5 & 2:3 respectively. At present the total of their salary is Tk. 4160. How much is the salary of A now?
উত্তর
Tk 1600
সমাধান
৩ : ৪ আগের বেতন এর অনুপাত,
ধরি, আগে ৩০০ এবং ৪০০ পেত।
আগে A ৩০০ পেলে এখন পায় = ৫/৪×৩০০ = ৩৭৫
আগে B ৪০০ পেলে এখন পায় = ৩/২×৪০০ = ৬০০
এখন পাওয়ার অনুপাত তাহলে ৩৭৫ : ৬০০
৩৭৫ক + ৬০০ক = ৪১৬০
৯৭৫ক = ৪১৬০
ক = ৪.২৬
তাহলে, A এর বেতন = ৩৭৫×৪.২৬ = Tk. 1600
২২৫৫৭
What is the angle between the hour and minute hand of clock when it is 12.20 pm by the clock?
উত্তর
1100
সমাধান
মধ্যবর্তী কোণ = | 11×20 - 60×12/2 |0
= | - 500/2|0
= 2500
So, the angel = 3600 - 2500 = 1100
২২৫৫৮
A reduction of 21% in the price of pulse enables a person to by 10.5 kg more for Tk. 100. How much is reduced per kg of pulse?
উত্তর
Tk 2
সমাধান
ধরি, original দাম = x Tk per kg
reduced দাম = 79x/100 Tk per kg
তাহলে, 100/(79x/100) - 100/x = 10.5
10000 - 7900 = 10.5 × 79x
x = 2100/(10.5×79)
তাহলে, required price = 79/100×2100/(10.5×79) = 2 Tk per kg
২২৫৫৯
A man lends Tk 10000 in four parts. If he gets 8% on tk 2000, 7.5% on Tk 4000 and 8.5% on Tk 1400, what percent must he get for the remainder, if the average interest is 8.13%?
উত্তর
9
সমাধান
Total interest পেতে হবে = 10000×8.13/100 = 813 টাকা।
এখন পর্যন্ত ( 2000 + 4000 + 1400) বা, 7400 টাকায় মোট interest = 2000×0.8 + 4000×0.75 + 1400×0.085 = 160 + 300 + 119 = 579 টাকা
তাহলে, টাকা পাওয়া বাকি ( 10000 - 7400) = 2600 , interest বাকি = 813 - 579 = 234
তাহলে, 2600 এর x% = 234 হলে
x = (234×100)/2600 = 9%
২২৫৬০
A man rows at 6 km/hr in still water and 4.5km/hr against current. His rate along the current is:
উত্তর
7.5 km/hr
সমাধান
along the current হচ্ছে current এর সাথে, তাহলে current তাকে row করতে সাহায্যে করবে। এটি হবে নিজের rate + current এর rate
এখন current এর rate = 6 - 4.5 = 1.5 km/hr
along rate = 6 + 1.5 = 7.5 km/hr