৭৬২১
Two bicycles start at the same time from points P and Q, moving toward each other. If the distance between P and Q is 120 km and their speeds are 12 km/h and 8 km/h respectively then after how much time will they meet each other?
উত্তর
6 hours
৭৬২২
Two pipes P and Q can fill a cistern in 15 and 20 minutes respectively. Both pipes are opened together, after how many minutes should Q be turned off, so that the cistern be fill in 12 minutes?
উত্তর
4 minutes
৭৬২৩
Working 5 hours a day, A can complete a work in 9 days and working 9 hours a day, B can complete the same work in 10 days. Working 6 hours a day, they can jointly complete the work in-
উত্তর
5 days
৭৬২৫
Three numbers are in the ratio 2 : 3 : 5, and their H.C.F. is 15. What is their L.C.M.?
উত্তর
450
৭৬২৬
There are 71 members in group A, 18 members in group B and 53 members in group C. All the members of these groups went to a restaurant. The average amount spent on each member of group A, B and C is Tk.397, Tk.421 and Tk.137 respectively. The total average amount (in Tk.) spent per member is-
উত্তর
Tk. 303
৭৬২৭
After 15 years, Rahul’s age will be five times what it was 5 years before. How old is Rahul now?
উত্তর
10 years
৭৬২৮
A can complete a piece of work in 6 days working 8 hours a day, and B can complete the same work in 12 days working 8 hours a day. How long will it take them to complete the work together if they work 4 hours a day?
উত্তর
8 days
৭৬২৯
A man rows downstream at 32 km/h and rows upstream at 22 km/h. At what speed can he row in still water?
উত্তর
27 km/h
৭৬৩০
Three mechanics A, B, and C can manufacture 120 units in 12, 20, and 30 hours respectively. What is the ratio of the time taken by A alone to complete the work to the time taken by all three working together to complete the same work?
উত্তর
2 : 1