Bangladesh Krishi Bank
Senior Officer Written Math Solution 2017
Exam Held on 20/01/2017
Math
Solution :
Q-1:
In a mixture the ratio of apples, peaches and grapes is 6:5:2. If the total
mixture is 39 pounds then what is the difference between apples and grapes?
Solution:
Let,
Apple, Peaches and Grapes 6x, 5x and 2x respectively.
Apple
= 39 (6x/13x)=18
Grapes
= 39 (2x/13x)=6
Difference
= 18-6 = 12 (Ans)
Q-2:
A man goes to his office at a certain time. If his waking speed is 5 kmh then
he is 7 minutes late. When his speed is 6kmh he reaches 5 minutes before. How
far his office from his house?
Solution:
Let,
total distance be x km
According
to the question,
x5-760
= x6 +560 [time = distancespeed]= 6 km
Q-3:
A man deposits 5000 tk at 5% annual interest for six months. In every six
months he withdraws tk 500 from his principal plus interest earned. What is the
total amount of interest he received?
Solution:
Semi
annual, so Interest rate= (5/2)%=2.5%
Total
Interest = 2.5%×5000 + 2.5%×4500 + 2.5%×4000 + 2.5%×3500 + 2.5%×3000 +
2.5%×2500 + 2.5%× 2000 + 2.5%×1500 + 2.5%×1000 + 2.5%×500
=2.5%×27500
=687.5
Tk.
Q-4:
A man interest and wages from his investment tk 5000. If he invests double then
the wages increased 50% and total amount is tk 8000. What is his actual income
in terms of wages and interest?
Solution:
Let,
Investment be x and Wages be y
According
to the question,
x+y=
5000 ….(i)
2x+1.5
y= 8000….(ii)
Now,
2×(i)-(ii)=>
We
get,
2x+2y=10000
2x+1.5y=8000
----------------------------------
0.5y=2000
=>
y=4000
and,
x+4000=5000
=>
x=1000
So,
Investment= 1000 and wages=4000 (Ans:)
Q-5:
20 men can finish a work in 30 days. After how many days can 5 persons leave
the work and the remaining work can be finished in 35 days?
Solution:
20
men can do in 30 days
1
man can do 30×20=600
Let,
5
men can do in x days
1
men can do in 5x days
Again,
20-5=15
men can do in 35-x days
1
men can do in 15(35-x) days
According
to the question,
5x
+ 15(35-x)=600, x= 15 (Ans)