A train crosses two bridges that are 420 meters and 200 meters long in 60 seconds and 40 seconds respectively. What is the length of the train?
A
200 meters
B
240 meters
C
280 meters
D
300 meters
উত্তরের বিবরণ
Let the train length = x meters.
Distances covered while crossing the bridges:-
First bridge: meters
-
Second bridge: meters
-
-
Time taken:
-
First bridge = 60 sec → speed =
-
Second bridge = 40 sec → speed =
-
-
Since speed is constant:
-
Solve for x:
Answer: The train is 240 meters long

0
Updated: 1 month ago
A mixture of 60 kg contains sand and stone in the ratio 7 : 5. Find the quantity of sand to be added to the mixture so that the ratio of sand to stone becomes 2 : 1.
Created: 1 month ago
A
10 liters
B
15 liters
C
18 liters
D
25 liters
Question: A mixture of 60 kg contains sand and stone in the ratio 7 : 5. Find the quantity of sand to be added to the mixture so that the ratio of sand to stone becomes 2 : 1.
Solution:
Quantity of sand = 60 × (7/12) = 35 kg
Quantity of stone= 60 - 35 = 25 kg
Let, x kg of sand be added to the mixture.
According to the question,
(35 + x)/25 = 2/1
⇒ 35 + x = 50
⇒ x = 50 - 35
⇒ x = 15

0
Updated: 1 month ago
৭ : ৬, ৬ : ৫ এবং ৪ : ৩ এই অনুপাতগুলোর মিশ্র অনুপাত কত?
Created: 1 month ago
A
১৭ : ৩১
B
৯ : ২৩
C
২৩ : ৩০
D
২৮ : ১৫
সমাধান:
দেওয়া আছে,
অনুপাতগুলো = ৪ : ৩, ৬ : ৫ এবং ৭ : ৬
অনুপাত তিনটির পূর্ব রাশিগুলোর গুণফল = (৪ × ৬ × ৭) = ১৬৮
অনুপাত তিনটির উত্তর রাশিগুলোর গুণফল = (৩ × ৫ × ৬) = ৯০
∴ নির্ণেয় মিশ্র অনুপাত = ১৬৮ : ৯০
= ২৮ : ১৫

0
Updated: 1 month ago
A sum of money is to be divided among P, Q, R, S in the ratio 7 : 3 : 5 : 2. If R gets Tk. 2000 more than S, what is Q's share?
Created: 1 month ago
A
TK. 2000
B
TK. 2200
C
TK. 2500
D
TK. 3000
Step 1: Let the shares of P, Q, R, S be proportional to 7 : 3 : 5 : 2
Let the common multiple be . Then:
-
P =
-
Q =
-
R =
-
S =
Step 2: Use the information given about R and S
Step 3: Find Q's share
Answer: Q's share = Tk. 2000

0
Updated: 1 month ago