1.If 15 toys cost Rs.234,what do 35 toys cost?
Sol:
No. of toys total cost
15 Rs.234
35 A
A=[15 toys then Rs234, 35(more) toys A( more) cost so min(15) will be denominater]
=(234x35)/15
Hence cost of 35toys is Rs.546/-
2.If 36 men can do a piece of work in 25 hrs,in how many hours will 15 men do it?
Sol:
No. of men working hrs
36 25hrs
15 A
A=[36 men then 25hrs ,15(less)men A(more) hrs so 15(min) will be denominater]
=(36x25)/15=60hrs
Hence 15 men can do a work in 60hrs/-.
3. If the wages of 6men for 15days be Rs.2100,then find the wages of 9 men for 12 days.
Sol:
Men days wages
6 15 2100
9 12 A
A=[6men then wages=Rs2100,9 men then more(A) wages so min (6)be denominater]&&[15days
then wages=Rs2100,12days then less(A) wages so max(15) will be denominater ]
=[9x12x2100]/(6x15)
4.If 9engines consume 24metric tonnes of coal,when each is working 8hrs a day,how much coal will be required for 8 engines,each running 13 hrs a day,it being given that 3engines of former type consume as much as 4 engines of latter type?
Sol:
No. of engines hrs in a day consumption ratio tonnes
9 8 1/3 24
8 13 1/4 A
A=[9engn=24tonnes then 8engn=less tonnes,so more (9) will be denominater]&&
[8hrs=24tonnes then 13hrs=more(A)tones so min(8) will be denominater]&&
[1/3=24 then ¼=less(A)tones so more(1/3) will be denominater]
=[{8x13x(1/4)}x24]/{9x8x(1/3)}=26tonnes