Question

Solve the problem first write a proportion. a) 15 is 60% of what number?b) what percent of 140 is 21?c) 8 is what percent of 40?d) 17.5 is what percent of 50?

Answer 1

a) 60% b) 15% c) 20% d) 35%

1) Let's set proportions for that, cross multiplying those ratios.

a)

x --------------- 100%

15---------------- 60%

60x =15*100

60x = 1500 Divide both sides by 60

x =25

Hence, 15 is 60% of 25

b) Similarly let's proceed with that, notice that there was a slight difference.

140 --------------100%

21 ---------- y

140y=2100

y=15%

Therefore, 21 is 15% of 140

c)

40---------- 100%

8 ----------- z

40z =800

z= 800/40

z =20%

Therefore, 8 is 20% of 40

d)

50 --------- 100%

17.5 ---------k

50k=1750

k =1750/50

k=35%

2) So, the answers are above in bold.