২২৯৫১
The number of bacteria in a colony was growing exponentially. At 1 pm yesterday the number of bacteria was 1000 and at 3 pm yesterday it was 4000. How many bacteria were there in the colony at 6 pm yesterday?
উত্তর
32,000
২২৯৫২
If 40% of all women are voters and 52% of the population is woman, what percent of the population are women voters?
উত্তর
20.8
সমাধান
মনে করি, মোট জনসংখ্যা = 100 জন
Women দের সংখ্যা = 52 জন
Women দের ভোটার সংখ্যা = 52×(40/100)
= 20.8
২২৯৫৩
A painter has painted one-third of a rectangular wall which is ten feet high. When he will paint another 75 square feet of that wall, he will have finished three-quarters of the job. What is the length (the horizontal dimension) of the wall?
উত্তর
18 feet
সমাধান
Given that hight of the wall is 10 m
Let Base of the wall is x m
Area of wall is 10x sq m
Three - quarter = 3/4
ATQ = According to the question
(3/4 - 1/3) part of wall = 75 sq m
So, 1 part of wall = 180 sq m
Rectangular base of the wall is 180/10 = 18 m
Ans. 18 m
২২৯৫৪
A chair originally cost Taka 50.00. The chair was offered for sale at 108% of its cost. After a week the price was discounted 10% and the chair was sold. The chair was sold for:
উত্তর
Taka 48.60
সমাধান
Offered price = 108% of 50 = 108/100×50 = 54 TK
Discounted price = 54 - 10% of 54 = 54 - 5.4 = 48.6 TK
২২৯৫৫
As labor costs, an electrician charges TK. 36.50 per hour for himself and TK. 27.50 per hour for his assistant. What would be the total labor cost for a job taking 61 hours?
উত্তর
TK. 4160.00
সমাধান
Cost per hour = 36.50 + 27.50 = 64 TK.
Total cost = 64×61 = 3904 TK
২২৯৫৬
An emergency vehicle travels 10 miles at a speed of 50 miles per hour. How fast must the vehicle travel on the return trip if the round-trip if travel is to be 20 minutes?
উত্তর
75 mph
সমাধান
Time spent = 10/50 hr = 1/5 hr = 1/5×60 min = 12 min
Time remaining = 20 - 12 = 8 min = 8/60 hr = 2/15 hr
Speed required at return - trip = 10/(2/15) miles/hour = 75 miles/hour
২২৯৫৭
Harun wants to buy a dress priced at TK. 89.75. If the sales tax is 8% , what is the total amount he must pay for the dress?
উত্তর
TK. 96.93
সমাধান
He must pay = 89.75 + 8% of 89.75 = 89.75 + 8/100×89.75 = 89.75 + 7.18 = 96.93 TK
২২৯৫৮
A company makes a profit of 6% on its first Tk. 1,000 of sales each day and Tk. 55 per thousand on all sales in excess of Tk. 1,000 for the day. How much profit will the company make in day when sales are Tk. 6,000?
উত্তর
335
সমাধান
For first 1,000tk , profit is = 1000×6100 = 60Remaining (6,000-1,000) or 5,000, profit is = 5000×551000 = 275Total Profit = 60+275 = 335 (Ans.)
২২৯৫৯
Ahsan travels for 6 hours at a rate of 50 miles per hour. His return trip takes 7.5 hours. What is his average speed for the whole trip?
উত্তর
44.5 mph
সমাধান
Total trip length = 2 × (50×6) = 2 × 300 = 600 miles
Total time needed = 6 + 7.5 = 13.5 hr
Average speed = 600 / 13.5 = 44.44 mph
২২৯৬০
A এবং B এর মোট বয়স B এবং C এর মোট বয়সের তুলনায় ১২ বছর বেশি। C,A এর চেয়ে কত বছরের ছোট?
উত্তর
12
সমাধান
A + B = B + C + 12A + B - B - C = 12A - C = 12