Per cent Wor d Pr oblems

Transcription

1 Per cent Wor d Pr oblems Ratio and proportion method Her e ar e sever al aids t hat will help you solve wor d pr oblems: 1. Make sur e you under st and t he quest ion t hat is asked 2. Sor t out t he inf or mat ion t o make a basic per cent pr oblem, such as 30% of what is 17? 3. Somet imes, you will have t o subt r act or add some of t he number s. 4. The base will always be t he or iginal number, pr ice, or t ot al. Some examples of per cent wor d pr oblems. A baseball pit cher won 80% of t he games he pit ched. I f he pit ched 35 ballgames, how many games did he win? 80% of 35 is what? Mult iply t he opposit es 80 x 35 = Divide by t he r emaining number games J er r y, an elect r ician, wor ked 7 mont hs out of t he year. What per cent of t he year did he wor k? (r ound answer t o t he near est hundr edt h) What per cent of 12 is 7? 12 mont hs = 1 year Mult iply t he opposit es 7 x = Divide by t he r emaining number % (r ounded t o hundr edt h) MLC page 1 of 8

2 Somet imes t he inf or mat ion needed t o solve a per cent wor d pr oblem is not st at ed dir ect ly. You will need t o sor t out t he number s given in t he pr oblem. Or ganizing all t he inf or mat ion int o a box f or mat will help you see what number s you have and what you need. Some examples. Ther e ar e 28 st udent s in a class. Sixt een of t hose st udent s ar e men. What per cent of t he class ar e women? (Round t o t he near est t ent h) Men % 16 Women % 12 Tot al % t ot al st udent s -16 men 12 women 12 is what % of 28? Mult iple t he opposit es x 12 = Divide by t he r emaining number % ` Donovan t ook a mat h t est and got 35 cor r ect and 10 incor r ect answer s. What was t he per cent age of cor r ect answer s? (Round t o t he near est hundr edt h) Cor r ect answer s % 35 I ncor r ect answer s % 10 Tot al answer s % cor r ect answer s +10 incor r ect answer s 45 t ot al answer s 35 is what % of 45? Mult iple t he opposit es x 35 = Divide by t he r emaining number % (r ounded t o hundr edt h) MLC page 2 of 8

3 Per cent Wor d Pr oblems Dir ect ions: Set up a basic per cent pr oblem. Somet imes you will have t o do ext r a st eps t o solve t he pr oblem. Follow r ounding dir ect ions. Answer s and solut ions st ar t on page 6. 1) A st udent ear ned a gr ade of 80% on a mat h t est t hat had 20 pr oblems. How many pr oblems on t his t est did t he st udent answer cor r ect ly? (r ound t o t he near est whole number ) 2) Ther e ar e 36 car pent er s in a cr ew. On a cer t ain day, 29 wer e pr esent. What per cent showed up f or wor k? (r ound t o t he near est t ent h) 3) A met al bar weighs 8.15 ounces. 93% of t he bar is silver. How many ounces of silver ar e in t he bar? (r ound t o t he near est t housandt h) 4) A woman put $ 580 int o a savings account f or one year. The r at e of int er est on t he account was 6½%. How much was t he int er est f or t he year in dollar s and cent s? (Round t o t he near est cent ) MLC page 3 of 8

4 5) A st udent answer ed 86 pr oblems on a t est cor r ect ly and r eceived a gr ade 98%. How many pr oblems wer e on t he t est, if all t he pr oblems wer e wor t h t he same number of point s? (Round t o t he near est whole number ) 6) Manuel f ound a wr ecked Tr ans-am t hat he could f ix. He bought t he car f or 65% of t he or iginal pr ice of $ What did he pay f or t he car? (Round t o near est dollar ) 7) Pamela bought an elect r ic dr ill at 85% of t he r egular pr ice. She paid $ f or t he dr ill. What was t he r egular pr ice? (Round t o t he near est cent ) 8) A cr ew is made up of 8 men; t he r est ar e women % of t he cr ew ar e men. How many people ar e in t he cr ew? 9) Ben ear ns $ 12,800 a year. About 15% is t aken out f or t axes. How much is t aken out f or t axes? MLC page 4 of 8

5 10) At a sale, shir t s wer e sold f or $ 15 each. This pr ice was 80% of t heir or iginal pr ice. What was t he or iginal pr ice? 11) Ther e ar e 32 st udent s in a class. Nine of t hose st udent s ar e women. What per cent ar e men? (r ound t o t he near est t ent h) 12) The Royals sof t ball t eam played 75 games and won 55 of t hem. What per cent of t he games did t hey lose? (r ound t o t he near est t ent h) MLC page 5 of 8

6 Answer Key x 20 = pr oblems x = % x 8.15 = ounces ½ x 580 = $ x 86 = pr oblems (r ounded t o near est whole) MLC page 6 of 8

7 x 7200 = 468, $ x = $ x 8 = , x 12,800 = 192, $ x 15 = MLC page 7 of 8

8 11. Tot al % 32 Men 23 Women 9 $ x 23 = %(r ounded t o near est t ent h) 12. Tot al % 75 Won 55 Lost x 20 = % games lost (r ounded t o t ent h) MLC page 8 of 8