২২৬৭১
If a +2b= 6 , ab =4 what is 2/a + 1/b?
উত্তর
3/2
সমাধান
a + 2b = 6; ab = 4⇒a + 2bab = 64⇒1b + 2a = 64 = 32
২২৬৭২
If two fair coins are flipped, what is the probability that one will come up heads and the other tails?
উত্তর
1/4
সমাধান
একটি coin toss করলে head/tail পাবার probability 12 ;দুইটির জন্য 12×12 = 14
২২৬৭৩
The number of different signals which can be given form 6 flags of different colours taken one or more at a time is
উত্তর
1956
সমাধান
6c1×1! + 6c2×2! + 6c3×3! + 6c4×4! + 6c5×5! + 6c6×6! = 1956
যেহেতু one or more at a time বলছে তাই নিজেদের মধ্যে ও factorial দিয়ে গুণ হয়েছে।
২২৬৭৪
The number of parallelograms that can be formed from a set of four parallel lines intersecting another set of three parallel lines is
উত্তর
6
সমাধান
এটি Solve করতে দ্রুত ছবিটি একে ফেলুন 6টি।
২২৬৭৫
Bus fare recently was increased form Taka 0.85 to Taka 1.00 what was the approximate percentage of increase?
উত্তর
18%
18%
সমাধান
increase = 1 - ·85·85×100% = 17·64% = 18%
২২৬৭৬
The next number in the sequence , 3, 6 m 11, 18, 27,.... is
উত্তর
38
সমাধান
প্রতিটি সংখা পাওয়া যাবে এর পূর্ববর্তী সংখ্যার সাথে কিছু সংখ্যা যোগ করে। এটা কিভাবে বের করে দেখুন -
3, 6, 11, 18, 27
3, 5, 7, 9
তাহলে পরবর্তী সংখ্যাটি পওয়া যাবে 27 + 11 = 38
২২৬৭৭
f(x) = -1, for all x>0. If f(a) = -1 and f(ab) = -1 then b =?
উত্তর
1
সমাধান
f(a)=-1f(ab)=-1then, ab=-1×1so f(b)=1
২২৬৭৮
A wholesaler bought 1200 pens for TK 18 each. He sold 60% of the pens for TK. 30 each and remaining for TK. 15 each. What was his average profit per pen?
উত্তর
TK. 6
সমাধান
Total cost = 1200×18 = 21600 TK.
Revenue from 60% pens = (60% of 1200)×30 = 720×30 = 21600 TK
Revenue from the rest of pens (40%) = (40% of 1200)×15 = 7200 TK
Total revenue = 21600 + 7200 = 28800 TK
Profit = 28800 - 21600 = 7200 TK.
Profit per pen = 7200/1200 = 6 TK
২২৬৭৯
Rahim, Karim and James paid a total TK. 45 for their dinner at a restaurant. If Rahim paid of the total amount, Karim paid TK. 17 and James paid the rest then what fraction of the total amount did James pay?
উত্তর
14
২২৬৮০
When Mr. Sen imports some raw materials he has to pay 7% import duty on the portion of the total value of the item in excess of TK. 1000. If the amount of import duty he paid was TK. 87.50 then what was the value of the raw material that he imported?
উত্তর
TK.2,250
সমাধান
Let the value of the raw material in excess of Tk 1000 be T.
Then, 7% of T = 87.5
or, 7/100 of T = 87.5
or, T = 87.5×100/7 = 1250 TK
So, value of the raw amterial = 1000 + 1250 = 2250 TK