Examples 5 to 8 of time and work
(5) A cistern has two taps which fill it in 10 minutes and 15 minutes respectively. There is also a waste pipe in the cistern. When all the three are opened, the empty cistern is full in 30 minutes. How long will the waste pipe take t…
(1) A can build a wall in 40 days, which B alone can build in 50 days. If they build it together and get a payment of Rs. 1125, what is B’s share ?
Solution.
Ratio of their Days = 40 : 50 =…
☼ Pipes ( may be inlet or may be outlet ) & Cisterns ( or tank or reservoir ) :
If a pipe can fill a t…
☼ Pipes ( may be inlet or may be outlet ) & Cisterns ( or tank or reservoir ) : If a pipe can fill a tank in x hrs. and another pipe can empty the full tank in y hrs ( where y > x ), then on opening both the pipes, the net […]
(5) If the wages of 12 men for 10 days be Rs. 2500, then find the wages of 15 men for 18 days.
Soln. M1 = 12 men, D1 = 10 days, W1 = Rs. 2500,
M2 = 15 men, D2 …
☼ Indirect Proportion : Two quantities are said to be indirectly proportional, if one the increase of the one, the other decreases proportionately.
e.g. (i) 10 men can do a piece of work in 6 days
∴ 15 …
☼ Direct Proportion : Two quantities are said to be directly proportional if on the increase or decrease of the one, the other increases or decreases proportionately.
e.g. (i) 7 ball pen cost Rs. 35
∴ 9 ” …