What is the value of 2x+4-4.2x+12x+2+2=?
Given that, 2x+4-4.2x+12x+2-1=2x×24-4×2x×212x+221 =16×2x-8×2x2x+2-1=8×2x2x+1=8×2x2x×21=8×2x2x×2=4
A pipe can fill up an empty tank in 15 minutes. Another pipe flows out 20 liter of water per minute. If the two pipes are opened together and the empty tank is filled in 135 minutes, how much water does the tank contain?
Let, the capacity of the tank be x liters. By 1st pipe In 15 minutes pipe fill=x part of the tank ∴In 1 minute pipe fill=x15 part of the tank
According to question, 135(x15-20)=x =135(x-30015)=x =9(x-300)=x =9x-2700=x =8x=2700 ∴x=27008=337.5 liters ∴The capacity of the tank is 337.5 liters.
Ms. Wazaiha invested a total amount of BDT 50,000 in two honds namely BEXIMCO and DBBL that pay annual interest at the rate of 6.5% and 9%, respectively. If she likes to receive BDT 4,000 as interest income, how much should she invest in each bond?
Let, she should invest x Tk. in BEXIMCO ∴She should invest = (50000 - x) Tk in DBBL According to question 6.5% of x + 9% of (50000 - x) = 4000 =6.5c100+9(50000-x)100=4000 =6.5x+450000-9x=4000000 =6.5x-9x=450000-4000000 =2.5x=50000 ∴x=500002.5=20000
∴The amount of BEXIMCO bond be 20,000 Tk. ∴DBBL amount would be = 50000 - 20000 = 30000Tk .
Faiyaz and Ehan are standing 90 yards apart on a north-south axis, Faiyaz walks 70 yards to west. Ehan walks 50 yards to the east, and then both stop. What is the straight-line distance in yards between them now?
Let, us depict the image according to question: Now, Faiyaz stands at point A And Ehan stands at point C Here, direct distance between them is AC △ABC is a right angle triangle where AC = Hypotenuse
∴Applying Pythagorean theorem, we get (AC)2=(AB)2+(BC)2 =(AC)2=(50+70)2+(90)2=(120)2+(90)2 =(AC)2=14400+8100=22500=(150)2 ∴AC=150 ∴The straight distance between Faiyaz and Ehan is 150 yards.
Suppose the number of people in Cumilla city is 1 million. If the number of males increases by 10% and the number of females decreases by 6%, then the number of people in city remains unchanged. What are the numbers of male and female in that city?
Let, number of male be x ∴Number of female be = (1000000 - x) According to question 110% of x + 94% of (1000000 - x) = 1000000 =110X100+94(1000000-X)100=1000000 =11X10+9.4(1000000-X)10=1000000 =11X+9400000-9.4X=10000000 =1.6X=10000000-9400000=600000 ∴X=6000001.6=375000 ∴Number of male = 3,75,000 ∴Number of female = 10,00,000-3,75,000 =6,25,000