Number & age problems, distance/rate/time, mixture, work, interest, geometry, and coin problems — all set up and solved algebraically with step-by-step explanations, equations, and verified answers.
Quick Values
Classic Examples
Numberssum=30, diff=6Numberssum=40, product=400Numbersdiff=8, product=105AgeAlice twice Bob futureAgesum = 50 years from nowAgeratio will be 2:1d=rttwo cars meetingd=rtcatch up (head start)d=rtfind time: 300km at 60d=rtround trip averageMixture30%+70%→50%Mixture20%+80% mix resultWorkA 3hr, B 5hr togetherWork3 workers togetherInterest$1000 @ 5% simple 3yrInterest$2000 compound 4% 10yrGeometryrect: P=50 find dimsGeometryrect: A=100, L=15Geometrytriangle: b=8, h=6GeometryHeron: a=3,b=4,c=5Geometrycircle: r=7Coinsquarters+dimes=$2.65, 20 coinsCoins12 quarters+dimes=$2.65
Steps Modes
None Answer only.
Summary Method names as pills.
Detailed Full accordion: problem setup, variable definition, equation, solution steps, and verification.
Problem-Solving Strategy
① Read — identify all given values
② Define — let x = unknown quantity
③ Translate — write the equation
④ Solve — algebraic manipulation
⑤ Verify — substitute back in
⑥ Answer — state with units
Problem Types Guide
x,y — Number
x+y=S, x−y=D → x=(S+D)/2
A+k — Age
In k years: A₀+k and B₀+k
d=rt — Distance
d=rt; meet: (r₁+r₂)t=d
c₁q₁ — Mixture
c₁q₁+c₂q₂=c_T(q₁+q₂)
1/t — Work
1/t₁+1/t₂=1/t_together
Prt — Interest
I=Prt; A=P(1+r)ᵗ
□△○ — Geometry
P=2(L+W); A=½bh; A=πr²
¢$ — Coins
Σ(value×count) = total value
Key Formulas
Sum+Diff\(x=\frac{S+D}{2},\;y=\frac{S-D}{2}\)
Age (twice)\(A_0+k=2(B_0+k)\Rightarrow k=A_0-2B_0\)
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.