A tape manufacturer reduces the price of his heavy duty tape
from Rs.30/- to Rs.28/- a reel and the price of a regular
tape from Rs.24/- to Rs.23/- a reel. A computing centre
normally spends Rs.1440/- a month for tapes and 3/4 of this
is for heavy duty tapes. How much will they save a
month under the new prices?
More descriptive way :-
The computer centre spends 3/4 of 1440 (ie,1080/-)for heavy duty tapes.
That means they are spending 360/- (ie,1440-1080) for regular tapes.
With 1080 Rs they can buy 36 units (ie,1080/30)
With 360 Rs they can buy 15 units (ie,360/24)
Again with the new prices :
To buy 36 units : 36*28= 1008
To buy 15 units : 15*23= 345
Total=1353
How much will they save a month under the new prices?
Ans= 1440-1353 = 87
More descriptive way :-
The computer centre spends 3/4 of 1440 (ie,1080/-)for heavy duty tapes.
That means they are spending 360/- (ie,1440-1080) for regular tapes.
With 1080 Rs they can buy 36 units (ie,1080/30)
With 360 Rs they can buy 15 units (ie,360/24)
Again with the new prices :
To buy 36 units : 36*28= 1008
To buy 15 units : 15*23= 345
Total=1353
How much will they save a month under the new prices?
Ans= 1440-1353 = 87
1440 * 3/4 = 1080
1080 / 30 = 36
1440 * 1/4 = 360
360 / 24 = 15
36 * 2 + 15 * 1 = 87