Aptitude - Volume and Surface Area - Discussion

Why we subtracted 10 here?

@Maruf Bd.

1 dm =10 cm.

Please, Clear me that 1 dm= How many cm?

On the Left-hand side, we have.

320*250*(110-x) which are all in cm so its cm cube.
while on Right-hand side, we have
8000 * 1000 m cube?

Why is that?

Consider fish tank on a flat surface, with very strong side glasses which is 5cm thick and the bottom glass thickness, is not given we have to find it. The fish comes out to measure his house length from OUTSIDE it notes that it is 3.3 m or 330cm in length, Now if the fish measured from inside it would get 10 cm less than 330 because the thickness 5+5 in two sides does not come into the picture. similarly, breadth, when measured outside it, was 260 cm from inside 10 cm less which is 250 . Height 110 cm from outside but bottom glass thickness is not known we have to find it let it be x which is 110-X ( Height of its house is small so it was able to jump outside LOL). Now amount of water, that is a volume that fits inside the tank is 8000 liters but we need it in cubic not in liters so for conversion multiply by 1000.

(Think if the glass walls were very thick said 8cm or more, then the volume of water would have fitted less than 8000 liters.). Always if we have the length, breadth and height measured from outside and volume is given and the walls have a certain thickness. we cannot directly apply l,b, h in the volume formula. if the question thickness is negligible then directly you can apply in the formula.

320+250+110-X=8000*1000.
X=10cm answer is in cm as we have converted l,b,h to cm.
Now centi is 10 power -2 which is 1/100 and deci is 10 power -1 which is 1/10
10 cm is nothing but 10 * 10 ^ -2 m = 10/100 which is nothing but 0.1
1dm is nothing but 1*10^-1 m =1/10 nothing but 0.1.

Note : mili = 10^-3= 1/1000, deci = 10^-1=1/10 , micro =10^-6= 1/1000000, centi=10^-2=1/100.

so 8000*1000= 320+250+ 110-X.

@Rani.

To convert it into cc.

10^-2 is equal to cm same as 10^-1 is equal to decimeter.

@Twinkle Nagar.

1dm means 1 decimeter.

Why 8000 is multiplied by 1000 here?

Our answer is 10 cm.

Then what is 1dm? Please, anybody tell me.