solve the questions plz !
 

shakir paid $7.50 to repair a toster rather than buy a new one for $30.what percent of the cost the new toster did he save?



Q:-2) in all pakistan weight lifting competition in multan,double of the first lift of mr.sahiwal was 150 kg more than his 2nd lift and sum of two lifts was 375 kg.what was the weight of his 1st lift?


q:- 3)if x+2y=11 and 2x+3y=17 then y is ?


q:-4)if 8 is 4 percent of k, then k is 4 percent of : ?


k symbol is for real number.

[QUOTE=SYEDA SABAHAT;331948]shakir paid $7.50 to repair a toster rather than buy a new one for $30.what percent of the cost the new toster did he save?



Q:-2) in all pakistan weight lifting competition in multan,double of the first lift of mr.sahiwal was 150 kg more than his 2nd lift and sum of two lifts was 375 kg.what was the weight of his 1st lift?


q:- 3)if x+2y=11 and 2x+3y=17 then y is ?


q:-4)if 8 is 4 percent of k, then k is 4 percent of : ?


k symbol is for real number.[/QUOTE]

q.1
new toaster=30$
repair of old=7.7$
%age of new saved= (30-7.5)/30 and multiply answer with 100=75% saved
q.2
suppose first lift=x
doble of first lift=2x
suppose second lift=y
according to condition double of x is y+150 so equation will be
2x=y=150 and
according to 2nd condition
x+y=150

now both equations are

2x=y+150 or 2x-y=150 and
x+y=375
multiply second equation with 2 and we will get 2x+2y=750
now subtract equation 1 from 2 and you will get 3y=600 or y=200

so 2nd lift is 200 kg ,put 200 in place of x in 2nd equation so
x+200=375
x=375-200=175 kg is first lift

q.3
if x+2y=11 and 2x+3y=17 then y is ?
multiply first equation with 2 so=2x+2y=22 now subtract 2x+3y=17 from it and answer will be y=5
q.4
if 8 is 4 percent of k, then k is 4 percent of : ?
8= 4/100 of k or 8= 4k/100 or 800=4k or k=800/4=200 now k=200
suppose k is 4% of x of k= 4x/100
put value of k which is 200, so 200=4x/100 or 200*100=4x or 20000=4x and finally x= 20000/4= 5000
so k is 4% of 5000

thats all i think

regards