heat loss from a surface can be reduced by polishing the surface coz polished surface is bad radiator and bad absorber of heat
21
Day 1: 30-3ft = 27+2ft = 29
Day 8: 23 jumps 3ft = 20 slips 2ft = 22
Day 16: 13 jumps 3ft = 10 slips 2ft = 12
Day 24: 3 jumps 3ft = Out?
It is assumed to be constant. Now, to cross past the pole, the train should cover a distance of x meters. Now, the time taken by the train to cross a platform of length 100 m is 25 seconds. Hence, the length of the train is 150 m.
17,19,23,29
the answer is 45 km/h
Define x:
Let the total distance be x.
Find the time needed in terms of x for speed at 30 km/h:
Find the time needed in term of x for 40 km./h:
Find the difference in time:
Solve x:
Find the total time needed to for the whole journey:
Given that he was 40 mins late:
Find the minimum speed needed:
Answer: The minimum speed is 45 km/h
1×2×…100=100!
Number of zeros in product of n numbers =[5n]+[52n]+[53n]+…
Number of zeros in product of 100 numbers =[5100]+[52100]+[53100]
where [.] is greatest integer function
=[20]+[4]+[0.8]=20+4=24
9 AND 3
Calculation:
⇒ If 1000 divided by 112, the remainder is 104. ⇒ 112 – 104 = 8 ⇒ If 8 is added to 1000 it will become the smallest four-digit number and a multiple of 112. ⇒ 1000 + 8 = 1008 ∴ The required result will be 1008.
Let the number be x.
So x-2 =15/x, or
x^2–2x-15=0, or
(x-5)(x+3)=0
Hence x = 5 or -3.
Check: When x=5, 5–2=3 which is 15/5=3.
When x=-3, -3–2=-5 which is 15/-3=-5.
The number is 5 or -3.
13 and 15
1%=50
12%=600
b)Brother or Sister
Because Bis related to either Brother or Sister.